Дисертації з теми "Downconversion; solar cell; silicon"
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1
Lu, Meijun. "Silicon heterojunction solar cell and crystallization of amorphous silicon." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 295 p, 2009. http://proquest.umi.com/pqdweb?did=1654494651&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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2
Park, Jihong. "Electrical properties of polycrystalline solar cell silicon." Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1061389017.
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3
Tobail, Osama. "Porous silicon for thin solar cell fabrication." Aachen Shaker, 2008. http://d-nb.info/992052904/04.
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4
Schnabel, Manuel. "Silicon nanocrystals embedded in silicon carbide for tandem solar cell applications." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:da5bbb64-0bcd-4807-a9f3-4ff63a9ca98d.
Повний текст джерелаАнотація:
Tandem solar cells are potentially much more efficient than the silicon solar cells that currently dominate the market but require materials with different bandgaps. This thesis presents work on silicon nanocrystals (Si-NC) embedded in silicon carbide (SiC), which are expected to have a higher bandgap than bulk Si due to quantum confinement, with a view to using them in the top cell of a tandem cell. The strong photoluminescence (PL) of precursor films used to prepare Si-NC in SiC (Si-NC/SiC) was markedly reduced upon Si-NC formation due to simultaneous out-diffusion of hydrogen that passivated dangling bonds. This cannot be reversed by hydrogenation and leads to weak PL that is due to, and limited by, non-paramagnetic defects, with an estimated quantum yield of ≤5×10-7. Optical interference was identified as a substantial artefact and a method proposed to account for this. Majority carrier transport was found to be Ohmic at all temperatures for a wide range of samples. Hydrogenation decreases dangling bond density and increases conductivity up to 1000 times. The temperature-dependence of conductivity is best described by a combination of extended-state and variable-range hopping transport where the former takes place in the Si nanoclusters. Furthermore, n-type background doping by nitrogen and/or oxygen was identified. In the course of developing processing steps for Si-NC-based tandem cells, a capping layer was developed to prevent oxidation of Si-NC/SiC, and diffusion of boron and phosphorus in nanocrystalline SiC was found to occur via grain boundaries with an activation energy of 5.3±0.4 eV and 4.4±0.7 eV, respectively. Tandem cells with a Si-NC/SiC top cell and bulk Si bottom cell were prepared that exhibited open-circuit voltages Voc of 900 mV and short-circuit current densities of 0.85 mAcm-2. Performance was limited by photocurrent collection in the top cell; however, the Voc obtained demonstrates tandem cell functionality.
5
Skarpeteig, Jon. "Cryogenic micro-photoluminescence of silicon solar cell materials." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11106.
Повний текст джерелаАнотація:
A literature review of relevant luminescence spectra for silicon solar cell materials has been performed. Three multi crystalline silicon samples in particular has been the focus of attention, one electronic grade sample R6, and two solar grade samples ES1, and MH2, where MH2 has added chromium. A list of relevant luminescence spectra has been compiled, and can be found in the appendix.The samples was measured using low temperature micro photoluminescence. They where cooled down by liquid helium in a cryostat, and excited using a laser. Photoluminescence was captured by a camera mounted on a spectrometer. Noise components was measured and removed, but are subject to changes in between measurements, causing some unwanted artifacts to appear in the end result.Luminescence due to P and B doping atoms are identified in ES1, and MH2 as expected, and a weak boron bound exciton line is also present in the clean sample R6. R6 also show signs of having a carbon-carbon complex impurity forming at grain boundaries. Lines attributed to chromium boron pairs where not observed in MH2, presumably due to the lack of such pairs. ES1 exhibits a luminescence attributed to a higher quality material, than both MH2, and R6. Expected behavior is for R6 to have such traits, but this is not the case. The reason for ES1 to show this enhanced luminescence is not known. Lines attributed to dislocations are observed in all the samples, but consist of less intense peaks than expected.Local heating is a severe problem using micro photoluminescence. Bound excitons, impurity lines, and dislocation related lines, all loose intensity at higher temperatures. The intrinsic TO line also have a substantial broadening with respect to energies, suggesting that local temperatures are as much as 70K higher than the sample holder temperature, when exciting with 128 mW using a 2 µm spot diameter.
6
Wu, Min. "Mechanical deformation of polycrystalline silicon for solar cell production." Thesis, University of Oxford, 2014. https://ora.ox.ac.uk/objects/uuid:68986f4a-f744-4936-a147-79b261863560.
Повний текст джерелаАнотація:
This thesis presents a feasibility study for producing silicon sheet for photovoltaic applications via traditional hot deformation in clean conditions using high purity materials. A special deformation rig has been designed and constructed for the compression tests. The cleanliness of the deformation conditions has been characterized and determined to be at a satisfactory level. Deformation of Czochralski, dislocation-free, single crystalline silicon along the < 100 > axis has been conducted to determine a suitable and achievable deformation condition. It has been found that single crystalline silicon can be uniaxially compressed by 30 % without severe cracking at temperatures above 1050 °C using a low average strain rate of ~10-5 s-1, the most uniform deformed microstructure has been obtained using an average stain rate of 1.67 x ~10-5 s-1. A dislocation density of order 1013 m-2 has been revealed by etch pit counting in an SEM. Dislocations with ½ < 110 > screw characters have been found using the TEM diffraction contrast technique. The most favourable post-annealing temperature has been determined to be 1400 °C. High purity polycrystalline, chemical vapor deposition (CVD) grown silicon has been successfully deformed at 1150 °C by 10 % at an average strain rate of 6.94 x 10-6 s-1. The as-received material has been found to have a strong < 110 > fiber texture as revealed by EBSD. Recrystallization occurs during pre-annealing at 1400 °C for 30 minutes. Approximately 90 % of the material recrystallizes with a complete disappearance of the fiber texture. Stacking faults have been mainly observed in the recrystallized material by TEM. It has been observed that the deformed polycrystalline material develops a second recrystallization texture when subjected to post-annealing at 1400 °C for 15 min, resulting in large grains up to several hundred microns in size and a low dislocation concentration of 5 x 1010 m-2. The HR-EBSD cross-correlation method has been employed to quantitatively investigate the GND density distribution in polycrystalline silicon. It has been found that the as-received material has a GND concentration up to 1015 m-2 and recrystallization during pre-annealing reduces the value to 1013 m-2. The minority carrier lifetime of the polycrystalline sample deformed at 1150 °C by 10 % followed by subsequent annealing at 1400 °C for 120 min has been measured using the QSS-PC method. A value of 1.9 μs at an injection level of 1 x 1012 cm-3 has been obtained, which corresponds to a minority carrier diffusion length of approximately 100 μm for electrons and 50 μm for holes. H-passivation has been found to be effective in improving the measured minority carrier lifetime. The results presented in this thesis suggest that producing silicon sheets for photovoltaic applications by conventional hot-deformation may be possible and should be a topic for further investigation.
7
Tobail, Osama [Verfasser]. "Porous Silicon for Thin Solar Cell Fabrication / Osama Tobail." Aachen : Shaker, 2009. http://d-nb.info/1161311378/34.
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8
Hudelson, George David Stephen III. "High temperature investigations of crystalline silicon solar cell materials." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50568.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Includes bibliographical references (p. 74-78).
Crystalline silicon solar cells are a promising candidate to provide a sustainable, clean energy source for the future. In order to bring about widespread adoption of solar cells, much work is needed to reduce their cost. Herein, I discuss the development of a new experimental technique to investigate solar cell materials under simulated processing conditions. I present the first applications and results using this technique, including observations of novel impurity interactions at elevated temperatures, and discuss their importance to the solar cell manufacturing process. One of the key drivers for reducing solar cell cost is developing a fundamental understanding of the behavior of defect and impurities in solar cell materials. Since solar cell processing occurs at high temperatures, experiments are needed that allow characterization of solar cell materials at high temperatures representative of manufacturing conditions, at the length-scales of the defects that are present. To achieve this, I have developed a novel in situ high temperature sample stage for measuring samples via synchrotron-based X-ray microprobe. This technique allows for mapping and chemical state determination of metal impurity clusters on the order of 100 nm to 100 [mu]m, over sample areas of several square millimeters, at temperatures in excess of 1200°C and under controlled ambient atmosphere. The application of this technique has yielded novel insights concerning the behavior of metal impurities at high temperature.
(cont.) For the first time, the phenomenon of retrograde melting (i.e. melting on cooling) has been observed in a semiconductor material. Internal gettering of dissolved metal to liquid metal-silicon droplets within the silicon matrix is observed. Understanding of this phenomenon provides the potential to improve solar cell devices by reducing the more-detrimental dissolved metal content within the material by concentrating it into precipitates. Finally, I provide results and a model that explains the formation and resulting morphology of mixed-metal silicide precipitates in multicrystalline silicon.
by George David Stephen Hudelson, III.
S.M.
9
Alderman, N. "Improving solar cell performance through surface modification of silicon." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/351353/.
Повний текст джерелаАнотація:
This project sets out to improve the efficiency of thin crystalline silicon solar cells by enhancing the photoexcitation through light harvesting, and by developing a novel surface passivation technique via the covalent attachment of organic molecules to the surface. To aid the characterisation of these novel structures, we have developed a new measurement technique for surface recombination using the Kelvin prove. A passivation method through the attachment of alkyl monolayers to the silicon surface has been developed. These layers were shown to have good passivation properties whilst retaining excellent resilience to oxidation. The passivation effect was determined to be caused by the generation of surface charge, as measured by the Kelvin probe. Further functionalisation of the organic monolayers was undertaken to attach fluorescent chromophores. A novel method for measurement of the surface recombination velocity was developed utilising the Kelvin probe. Changing the incident photon flux, and thus the photogenerated current, allows measurement of the surface recombination current through the change in surface photovoltage. This dependence can then be used to extract the value of the surface recombination velocity. Furthermore, we have shown that this method can be developed further into a mapping technique for surface recombination lifetime, of potentially significant industrial interest. The effect of the silicon surface charge on the passivation observed has been investigated through the attachment of charged monolayers. It was found that through the attachment of a positive charge, the observed recombination lifetime in n-type silicon decreased whilst a negative charge (through the attachment of carboxylic acid groups to the surface) was found to improve the surface passivation. The carboxylic acid functional groups were charged through immersion in triethylamine (base) and returned to the neutral, starting state through immersion in acetic acid. We have found that the recombination lifetime decreases linearly with decreasing charge-surface distance. This technique allows an in-depth study of surface passivation to be carried out by separating the two principal causes for passivation – the removal of surface states and charge attachment to the surface. Fluorescent chromophores were attached to the silicon surface by two different techniques – through the reaction of an alcohol-terminated monolayer with an acyl chloride porphyrin and by palladium-catalysed cross-coupling of an allyl-terminated surface with a cyanine dye. The fluorescence quenching was investigated at various chromophore-silicon distances by varying the length of the alkyl chain spacer. We find that the fluorescence lifetime decreases with decreasing chromophore-silicon distance, and follows a logarithmic trend. Further work is required, however, to combine sensitisation with surface passivation as incorporation of a sensitisation layer by the palladium cross coupling of an allyl-terminated surface results in metal contamination to the surface, reducing recombination lifetime.
10
Gold, Scott Alan. "Nitrogen incorporation in thin silicon oxide films for passivation of silicon solar cell surfaces." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/11101.
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11
Mohammadi, Farid. "A Meta-Analysis on Solar Cell Technologies." Thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-32584.
Повний текст джерелаАнотація:
The objective of this study is analysing the characteristics of five different solar cell technologies regarding their efficiency, fill factor, cost and environmental impacts and comparing their improvement records over years considering their efficiency. The five solar cell technologies of interest are amorphous silicon, monocrystalline silicon, polycrystalline silicon, cupper indium gallium selenide thin film and cadmium telluride thin film. The structure and manufacturing process of each of cell technologies were discussed. The study was conducted by the aid of available scientific reports regarding the electrical characteristics of different solar cell technologies. The extracted information regarding efficiency rate and fill factor was analysed using graphs and significant findings are discussed. The five technologies are also compared regarding their cost and ease of fabrication and their impacts on environment and recycling challenges. The result of this study is suggesting the most promising technology that may be the optimal option for further investment and research.
12
Utama, Roland Yudadibrata Photovoltaics & Renewable Energy Engineering Faculty of Engineering UNSW. "Inkjet printing for commercial high efficiency silicon solar cells." Publisher:University of New South Wales. Photovoltaics & Renewable Energy Engineering, 2009. http://handle.unsw.edu.au/1959.4/43711.
Повний текст джерелаАнотація:
One way of reducing the cost of crystalline silicon solar cell fabrication is by increasing the conversion efficiency of the device. However, most high efficiency solar cell designs require more complex fabrication methods that also increase the fabrication cost. Photolithography is an example of such an indispensable but costly process. The most common use for photolithography in solar cell fabrication is for dielectric patterning. In this thesis, inkjet printing is proposed as an alternative method for dielectric patterning in solar cell fabrication. There are two inkjet printing methods developed in this thesis. The indirect inkjet patterning method involves the deposition of a suitable plasticiser droplet onto an intermediate resin coating layer on top of the dielectric surface. Diethylene glycol and novolac resin are used as the plasticiser and coating layer respectively. The plasticiser changes the permeability of the affected region of the resin such that it becomes permeable to liquid dielectric etchants. When the resin layer is removed, the printed pattern is transferred to the dielectric layer. The optimised process produces round openings with diameters as small as 30-35 μm and continuous line patterns with width as narrow as 40-50 μm. The direct inkjet patterning method involves the deposition of liquid phosphorus dopant sources onto both silicon and dielectric surfaces. Two types of phosphorus sources are used: phosphoric acid and specially-formulated dopant sources. Narrow lines as wide as 15-20 μm are produced after appropriate surface treatments on both silicon and dielectric surfaces. Using this method, a process that simultaneously pattern the dielectric layer and diffuse the silicon underneath is developed. Various high efficiency solar cell structures such as selective emitter, localised contacts, surface texturing and edge isolation are demonstrated using the indirect inkjet patterning method. Both inkjet patterning methods are then used in the fabrication of a selective emitter solar cell. Fill factors in the range of 0.79-0.80 are shown to be achievable with both patterning methods, thus indicating the high quality metal-silicon contacts formed by these inkjet techniques.
13
Henriksen, Lisa Grav. "Pump-probe experiments of multicrystalline silicon for solar cell applications." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19207.
Повний текст джерелаАнотація:
In order to make cost effective solar cells from mc-Si materials, the negative contributions from defects and impurities should be reduced. The analysis of the photogenerated carrier properties is therefore of great importance for characterising carrier processes and hence, for improving the material performance.In this work, pump-probe measurement of a range of silicon wafers have been performed, using anultrafast laser of 800 nm wavelength and 85 fs pulses. The optical response in the samples were analysed by measuring the reflected probe beam initial transient.The purpose of this theses was to explore the use of pump-probe experiment to study carrier dynamics in mc-Si. Measurements of single c-Si samples were used as a basis for developing good experimental skills as well as achieving knowledge about carrier dynamics in c-Si. The initial Delta R/R was studied for a range of input parameters, aiming to characterise important contributions to the measurements.The effects of passivation has been studied, indicating a significant contribution to R~R. Etchingoff the passivated layer of an oxide (SiO2) wafer, showed a radically increased in pump beam reflectivity, from 9% to 32%, and a reduced DeltaR~R from 47×10-6 to 37×10-6 was be observed. Analysis has showed that incident angle may be chose such that the pump reflection loss is at a minimum for the given passivation thickness.The final results showed a R~R is in the range of (14-41)e-6 for bare c-Si, and (47-171)e-6 for passivated c-Si wafers.Ultrafast initial recovery has been observed for mc-Si samples, and attributed to trapping of carriers. Decay times in the range of 1-6 ps are deduced and trapping densities are found as (1:3 - 4:3) × 10^18 cm-3, which is in the same order as the excitation densities.A methodology for using pump-probe measurements to analyse mc-Si samples is established, and the technique is used in characterising the observed defect states, which is of great interest for improving solar cell materials.
14
Ekstrøm, Kai Erik. "Growth and Characterization of Silicon Nanowires for Solar Cell Applications." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18337.
Повний текст джерелаАнотація:
Si-nanowires are being introduced as an attempt to decrease the high recombination rate present in silicon based thin-film solar cells by employing radial pn-junctions instead of conventional planar pn-junctions. Previous publications have also shown an additional increase in the amount of absorbed light when covering a silicon-substrate in silicon nanowires which may result in a further increase in the total efficiency of a thin-film solar cell. Successful growth of Si-nanowires has earlier been performed by Chemical Vapour Deposition (CVD), employing gold (Au) as catalytic material. Au is a very stable catalytic material for nanowire growth but Au-residues are unwanted in solar cell applications, and the current experiment has therefore investigated aluminium (Al) as an alternative catalyst material. However, stable Al-catalysed growth has been proven to be difficult and is assumed to be mainly due to rapid oxidation of Al to Al2O3. Most of the nanowires were short, tapered and consisted of worm-like structures. Several unsuccessful in-situ NH3-based cleaning (CVD) processes were attempted. Tin (Sn) was also attempted as a protective coating for the Al-film in order to protect Al from exposure to air during sample transport, without any luck. As solar cells require both p-doped and n-doped sections in order to form pn-junctions, initial investigations were performed on the effect from the addition of dopant gases (B2H6 and PH3) on nanowire morphology. The addition of B2H6 to the gas flow seemed to have much larger effects than PH3 on the nanowire morphology compared to intrinsic nanowires. Both gases resulted in a continuous reduction in the average nanowire length with increasing dopant⁄SiH4 ratios, ultimately leading to a complete inhibition of nanowire growth. The highest usable dopant⁄SiH4 ratios before complete growth-inhibition were found to ~10^-3 for B2H6 and ~10^-1 for PH3. An undesirable tapering effect was also found when adding B2H6 to the gas-flow, resulting in radial growth of amorphous silicon on the nanowire walls already at the lowest dopant ratio (~10^-5). This may complicate the use of B2H6 as a dopant gas for p-type nanowires. Ignoring the fact that the addition of PH3 to the gas-flow reduces the nanowire growth rate PH3 may be assumed to be a good alternative for n-type doping of nanowires as no further effects on the nanowire morphology is observed. The actual implementation of dopant atoms into the nanowire structure may be determined by measuring the electrical resistivity in the nanowire, and a possible four-contact structure has been designed and partly optimized for this purpose. The contact structure has been designed in three layers where two of them are produced by photolithography while the smallest layer by electron-beam-lithography. Note that the structure has not been finalized because of time limitations. Some optimization of the four nanowire contacts remains as some final lift-off problems appeared, and is assumed to be related to either an incomplete development of the smallest features or an observed resist-bubbling because of high Titanium (Ti) deposition temperature. However, a robust three-point alignment procedure has been investigated and found useful for producing accurate contacts to single nanowires and leads to the conclusion of a promising structure.
15
Morishige, Ashley E. (Ashley Elizabeth). "Co-optimizing silicon solar cell processing for efficiency and throughput." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85481.
Повний текст джерелаАнотація:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 67-71).
Crystalline silicon solar cells are a proven renewable energy technology, but they have yet to reach low costs commensurate with subsidy-free, grid-scale adoption. To achieve the widespread adoption of photovoltaics, the cost per unit of electricity must be reduced by increasing solar cell efficiency. Parts per trillion concentrations of iron impurities in the silicon material can severely limit solar cell efficiency. Iron can be found in both precipitated and point defect form in silicon. Both forms are detrimental to final solar cell efficiency, but their negative impact can be mitigated during solar cell processing. In a standard solar cell process, the phosphorus diffusion step is the key opportunity to redistribute iron impurities because it is the step with the largest thermal budget. Phosphorus diffusion process optimization for solar cell material so far typically consists of one or more isothermal steps followed by a cooling step. Iron silicide precipitates can be dissolved at high temperatures, whereas at lower temperatures, interstitially dissolved iron is driven to the phosphorus-rich layer. Previous optimizations typically maximize minority carrier lifetime without constraining process time and device parameters. This thesis explores a novel phosphorus diffusion process in which there are no isothermal steps. The goal of this work is to demonstrate simultaneous maximization of minority-carrier lifetime, while maintaining high process throughput and steady emitter sheet resistance. Predictive simulation, electrical characterization techniques, and synchrotron-based X-ray fluorescence were combined to compare this new processing approach to standard solar cell processing. This continuously ramped temperature processing may be a promising approach for maximizing solar cell performance, maintaining reasonable manufacturing rates, and achieving a target sheet resistance.
by Ashley E. Morishige.
S.M.
16
Schumacher, Jürgen Otto. "Numerical simulation of silicon solar cells with novel cell structures." [S.l. : s.n.], 2000. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB9170598.
Повний текст джерела
17
Al-Taay, Hanaa. "Growth and characterization of silicon nanowires for solar cell applications." Thesis, Al-Taay, Hanaa (2014) Growth and characterization of silicon nanowires for solar cell applications. PhD thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/23299/.
Повний текст джерелаАнотація:
Silicon nanowires (SiNWs) have received considerable attention as base materials for third-generation photovoltaic (PV) devices because they lend themselves to large- scale production with enhanced light trapping and increased overall performance. Previous studies have grown SiNWs on indium tin oxide-coated glass substrates by the pulsed plasma-enhanced chemical vapour deposition method (PPECVD) using tin (Sn), aluminum (Al), gold (Au) and zinc (Zn) as catalysts.
Various catalysts (Sn, Zn, Au and Al) with thin film thicknesses from 10nm to 100nm, were used in this study of SiNW growth. Surface morphology analysis, by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), of the grown SiNWs showed the influence of the catalyst type and thickness. The wires became thicker and shorter as the catalyst thickness increased. However, the SiNWs catalyzed by Al metal were thicker than those grown using Sn, Au and Zn metals. The density of the SiNWs decreased as the catalyst thickness increased. For example, the 10nm thick Al catalyst produced the greatest SiNW density of 20NW/μm2, whereas the 100nm-thick Au resulted in the lowest density of 6NW/μm2.
The effect of catalyst type and thickness on the structural properties of the grown SiNWs was investigated through X-ray diffraction (XRD). The XRD measurements showed that the SiNWs grown with Au catalysts had higher crystallinity than those grown using other catalysts. Moreover, the diffraction peaks became sharper with increasing wire diameter, indicating that the crystallinity of the grown SiNWs was enhanced. The optical properties of the prepared SiNWs were investigated by photoluminescence (PL) and Raman spectra. A red emission band was clearly observed in the PL spectra of all the prepared SiNWs. In the Raman spectrum, the first-order transverse optical mode (1TO) was exhibited in all SiNWs catalyzed using Sn, Au, Al and Zn. However, the 1TO peak location depended on the catalyst type and thickness. Important results were observed at a catalyst thickness of 80nm for all catalysts because the 1TO Raman peak was closest to the crystalline Si peak location for all the prepared samples, except for the SiNWs prepared using 100nm of Au metal.
The crystal size of the grown SiNWs was calculated from the Raman spectra. In general, the crystal size of the grown SiNWs using 10, 20, 40, 60 and 100nm of Sn, Al and Zn metals decreased with increasing thickness of catalyst. However, the SiNWs prepared using 80nm thick Sn, Al and Zn catalysts had the largest crystal size. In contrast, the crystal size of SiNWs catalyzed by Au increased with increasing the catalyst thickness.
Several designs of solar cells based on SiNWs were fabricated by the PPECVD method at 400°C on an ITO-coated glass substrate using the two most promising catalysts, Zn and Au. The first one was a p-type SiNWs/i-amorphous Si/n-type amorphous Si (p-i-n) structure using the Zn catalyst. The photocurrent density of the fabricated device was 13.3mA/cm2 and the open-circuit voltage was 0.5V. A high- performance nanowire solar cell fabricated in this work had 2.05% light conversion efficiency.
The other device structures were fabricated by doping SiNWs catalyzed with Zn and Au as p and n type to fabricate p-n homo-junction SiNW solar cells. The fabricated pn junction solar cell based on the Zn-catalyzed SiNWs showed a higher efficiency of 1.01% compared with the Au catalyzed SiNW solar cell with an efficiency of 0.67%. These promising results provide a basis for further studies aimed at optimizing the device designs.
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Osorio, Ruy Sebastian Bonilla. "Surface passivation for silicon solar cells." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:46ebd390-8c47-4e4b-8c26-e843e8c12cc4.
Повний текст джерелаАнотація:
Passivation of silicon surfaces remains a critical factor in achieving high conversion efficiency in solar cells, particularly in future generations of rear contact cells -the best performing cell geometry to date. In this thesis, passivation is characterised as either intrinsic or extrinsic, depending on the origin of the chemical and field effect passivation components in dielectric layers. Extrinsic passivation, obtained after film deposition or growth, has been shown to improve significantly the passivation quality of dielectric films. Record passivation has been achieved leading to surface recombination velocities below 1.5 cm/s for 1 Ωcm n-type silicon covered with thermal oxide, and 0.15 cm/s in the same material covered with a thermal SiO2/PECVD SiNx double layer. Extrinsic field effect passivation, achieved by means of corona charge and/or ionic species, has been shown to decrease by 3 to 10 times the amount of carrier recombination at a silicon surface. A new parametrisation of interface charge, and electron and hole recombination velocities in a Shockley-Read-Hall extended formalism has been used to model accurately silicon surface recombination without the need to incorporate a term relating to space-charge or surface damage recombination. Such a term is unrealistic in the case of an oxide/silicon interface. A new method to produce extrinsic field effect passivation has been developed in which charge is introduced into dielectric films at high temperature and then permanently quenched in place by cooling to room temperature. This approach was investigated using charge due to one or more of the following species: ions produced by corona discharge, Na+, K+, Cs+, Mg2+ and Ca2+. It was implemented on both single SiO2 and double SiO2/SiNx dielectric layers which were then measured for periods of up to two years. The decay of the passivation was very slow and time constants of the order of 10,000 days were inferred for two systems: 1) corona-charge-embedded into oxide grown on textured FZ-Si, and 2) potassium ions driven into an oxide on planar FZ-Si. The extrinsic field effect passivation methods developed in this work allow more flexibility in the combined optimisation of the optical properties and the chemical passivation properties of dielectric films on semiconductors. Increases in cell Voc, Jsc and η parameters have been observed in simulations and obtained experimentally when extrinsic field effect passivation is applied to the front surface of silicon solar cells. The extrinsic passivation reported here thus represents a major advancement in controlled and stable passivation of silicon surfaces, and shows great potential as a scalable and cost effective passivation technology for solar cells.
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Forster, Maxime. "Compensation engineering for silicon solar cells." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00876318.
Повний текст джерелаАнотація:
This thesis focuses on the effects of dopant compensation on the electrical properties of crystalline silicon relevant to the operation of solar cells. We show that the control of the net dopant density, which is essential to the fabrication of high-efficiency solar cells, is very challenging in ingots crystallized with silicon feedstock containing both boron and phosphorus such as upgraded metallurgical-grade silicon. This is because of the strong segregation of phosphorus which induces large net dopant density variations along directionally solidified silicon crystals. To overcome this issue, we propose to use gallium co-doping during crystallization, and demonstrate its potential to control the net dopant density along p-type and n-type silicon ingots grown with silicon containing boron and phosphorus. The characteristics of the resulting highly-compensated material are identified to be: a strong impact of incomplete ionization of dopants on the majority carrier density, an important reduction of the mobility compared to theoretical models and a recombination lifetime which is determined by the net dopant density and dominated after long-term illumination by the boron-oxygen recombination centre. To allow accurate modelling of upgraded-metallurgical silicon solar cells, we propose a parameterization of these fundamental properties of compensated silicon. We study the light-induced lifetime degradation in p-type and n-type Si with a wide range of dopant concentrations and compensation levels and show that the boron-oxygen defect is a grown-in complex involving substitutional boron and is rendered electrically active upon injection of carriers through a charge-driven reconfiguration of the defect. Finally, we apply gallium co-doping to the crystallization of upgraded-metallurgical silicon and demonstrate that it allows to significantly increase the tolerance to phosphorus without compromising neither the ingot yield nor the solar cells performance before light-induced degradation.
20
Es, Firat. "Fabrication And Characterization Of Single Crystalline Silicon Solar Cells." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612363/index.pdf.
Повний текст джерелаАнотація:
The electricity generation using photovoltaic (PV) solar cells is the most viable and promising alternative to the fossil-fuel based technologies which are threatening world&rsquos climate. PV cells directly convert solar energy into electrical power through an absorption process that takes place in a solid state device which is commonly fabricated using semiconductors. These devices can be employed for many years with almost no degradation and maintenance. PV technologies have been diversified in different directions in recent years. Many technologies with different advantages have been developed. However, with more than %85 percent market share, Si wafer based solar cells have been the most widely used solar cell type. This is partly due to the fact that Si technology is well known from the microelectronic industry. This thesis is concerned with the production of single crystalline silicon solar cells and optimization of process parameters through the characterization of each processing step. Process steps of solar cell fabrications, namely, the light trapping by texturing, cleaning, solid state diffusion, lithography, annealing, anti reflective coating, edge isolation have all been studied with a systematic approach. Each sample set has been characterized by measuring I-V characteristics, quantum efficiencies and reflectance characteristics. The best efficiency that we reached during this study is 10.37% under AM1.5G illumination. This is below the efficiency values of the commercially available solar cells. The most apparent reason for the low efficiency value is the series resistance caused by the thin metal contacts. It is observed that the efficiency upon the reduction of series resistance effect is reduced. We have shown that the texturing and anti-reflective coating have a critically important effect for light management for better efficiency values. Finally we have investigated the fabrication of metal nanoparticles on the Si wafer for possible utilization of plasmonic oscillation in them for light trapping. The self assembly formation of gold nanoparticles on silicon surface has been successfully demonstrated. The optical properties of the nanoparticles have been studied
however, further and more detailed analysis is required.
21
Al-Juffali, Abdullah Ali S. "Modelling, simulation and optimisation of back contact silicon solar cells." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329638.
Повний текст джерела
22
Jin, Chen. "Interdigitated back contacts solar cell based on thin crystalline silicon substrates." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/666246.
Повний текст джерелаАнотація:
This thesis contributes to the fabrication technology of c-Si solar cells on thin substrates based on Interdigitated Back-Contacted (IBC) structures. The potential of this structure to obtain high efficiencies is well-known. However, important challenges should be addressed to adapt it to thin c-Si substrates, such as the manufacturing of the thin c-Si substrate itself, light absorption enhancement, device structure design, surface passivation, etc. Focused on these challenges, experiments and simulations have been carried out, including innovative thin c-Si substrate fabrication method Millefeuille process, novel IBC solar cell structures combining laser doping and silicon heterojunction technologies and thin IBC solar cell performance prediction through simulation. Finally, a 30 µm thick c-Si solar cell is fabricated by thinning down a finished device applying a silicon etching technique that combines dry and wet etching. Considering the Millefeuille process, based on the technological know-how the impact of both modulated profile and periodicity of silicon pores on the generated thin layer quality is explored and the results are visualized by SEM images. Furthermore, the solid-void transformation evolution during the high temperature annealing reveals the pore status at 35, 60 and 90 minutes, allowing a deeper understanding of the practical silicon atomic surface diffusion and the shape evolution. In order to find a viable and promising device structure that can be used in case of thin silicon substrates, a hybrid p-type solar cell structure is reported. In this case, emitter is based on silicon heterojunction technology while the base contacts are created by laser processing Al2O3/SiCx films. Special attention of the compatibility of both technologies has been paid in the proposed fabrication process including emitter region re-passivation and contact metallization. This work provides a new approach for achieving low-temperature high efficiency c-Si solar cells, as well as a novel pathway compatible to the fabrication of IBC devices based on thin c-Si substrate.In parallel with experimental progress, the simulation on thin c-Si IBC solar cell is carried out for performance study and prediction involving two typical rear surface doping structures: fully- and locally-doped. Simulation results of fully-doped structure reveal an efficiency potential of 16-17 % for thin c-Si IBC solar cell based on substrates of 10-15 µm without changing the technology developed for thick ones. Regarding the locally-doped structure, its performance is less tolerant to the degradation of front surface passivation. Additionally, a strong reduction of short-circuit current related to stronger requirements in the effective diffusion length is also deduced. Finally, a reduction of saturation current density, probably related to a change in the distribution of current that flow parallel to the rear surface, is also observed when the device is slimmed down. Next, a thin IBC c-Si solar cell efficiency potential is explored through rear contacts pitch study and the highest conversion efficiency is expected when contact pitches are minimum in the range of study. Finally, efforts are paid to get a thin c-Si solar cell through thinning down an already finished device of thick substrate. A silicon etching process based on RIE and wet chemical etching is proposed. Different experiments demonstrate that the front surface can be successfully repassivated after etching process. Additionally, random pyramids are created on that surface and the optical response of thin c-Si substrates is measured revealing a potential photogenerated current in the range of 40 mA/cm2 for 30 µm-thick substrates. Applying all these techniques to a final device, a 12.1 % efficiency is achieved and the front surface recombination velocity is deduced to be 1500 cm/s by comparing EQE with simulation results.Esta tesis contribuye a la tecnología de fabricación de células solares de silicio cristalino (c-Si) en sustratos delgados basados en estructuras interdigitadas de contacto posterior (IBC). El potencial de esta estructura para obtener altas eficiencias es bien conocido, pero deben abordarse desafíos importantes para adaptarlo a sustratos finos de c-Si como son: la fabricación del propio sustrato delgado de c-Si, la mejora de la absorción de luz, el diseño de la estructura del dispositivo, la pasivación superficial, etc. Centrándose en estos desafíos, en esta tesis se han llevado a cabo experimentos y simulaciones que incluyen: mejora del método innovador de fabricación de sustratos de c-Si fino Millefeuille, estructuras novedosas de células solares IBC compatibles con sustratos delgados y predicción del rendimiento de células solares delgadas IBC mediante simulación. Finalmente, se ha fabricado una célula solar de c-Si de 30 µm de espesor adelgazando un dispositivo terminado.Considerando el proceso de Millefeuille, se ha explorado el impacto del perfil modulado y la periodicidad de los poros de silicio en la calidad de la capa delgada generada. Además, se ha observado mediante SEM la evolución del poro durante el recocido a alta temperatura, lo que permite una comprensión más profunda de la difusión de la superficie atómica del silicio y la evolución de la forma.Con el fin de encontrar una estructura de dispositivo viable y prometedora que se pueda usar en el caso de sustratos de silicio delgado, se ha desarrollado una estructura de célula solar de tipo p híbrida. En este caso, el emisor se basa en la tecnología de heterounión de silicio, mientras que los contactos de base se crean mediante el procesado láser de capas de Al2O3/SiCx. Se ha prestado especial atención a la compatibilidad de ambas tecnologías en el proceso de fabricación propuesto alcanzándose eficiencias del 19 %.Paralelamente al progreso experimental, se ha llevado a cabo simulación en células solares finas IBC de c-Si con el objetivo de predecir su rendimiento para dos estructuras típicas de dopaje en la superficie posterior: dopado total y dopado local. Los resultados de la simulación de la estructura completamente dopada revelan un potencial de eficiencia del 16-17% para las células solares finas IBC basadas en sustratos de 10-15 µm sin cambiar la tecnología desarrollada para las gruesas. Con respecto a la estructura con dopado local, se deduce una fuerte reducción de la corriente de cortocircuito relacionada con unos requisitos más fuertes en la longitud de difusión efectiva. Finalmente, también se observa una reducción de la densidad de la corriente de saturación, probablemente relacionada con un cambio en la distribución de la corriente que fluye paralelamente a la superficie posterior cuando el dispositivo se adelgaza. A continuación, se explora la eficiencia de la célula solar delgada IBC de c-Si a través del estudio de la distancia de los contactos traseros. La mayor eficiencia de conversión se espera cuando la distancia entre contactos es mínima en el rango de estudio (200-250 µm).Finalmente, se fabrica una célula solar delgada de c-Si mediante el adelgazamiento de un dispositivo ya terminado en un sustrato grueso. Se propone un proceso de ataque de silicio basado en una combinación de RIE más ataque químico húmedo. Diferentes experimentos demuestran que la superficie frontal puede ser repasivada exitosamente después del proceso de ataque. Además, se crean pirámides aleatorias en esa superficie y se mide la respuesta óptica de los sustratos finos de c-Si revelando un potencial de corriente fotogenerada en el rango de 40 mA/cm2 para sustratos de 30 µm de espesor. Aplicando todas estas técnicas a un dispositivo final, se logra una eficiencia del 12,1% y se deduce que la velocidad de recombinación de la superficie frontal es de 1500 cm/s comparando la EQE con los resultados de la simulación
23
Karaman, Mehmet. "Characterization And Fabrication Of Silicon Thin Films For Solar Cell Applications." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613598/index.pdf.
Повний текст джерелаАнотація:
In this thesis study, fabrication and characterization of silicon thin films
prepared by magnetron sputtering and electron beam evaporation for solar
cell applications have been investigated. In the first part of the study,
magnetron sputtering method was used to fabricate thin hydrogenated
amorphous silicon (a-Si:H) film on a Si substrate. Some samples were
prepared on glass substrate for the basic characterizations like transmission
and resistivity. Dark and illuminated I-V characteristics of the silicon
heterojunction (SHJ) solar cells were studied as a function of material type
and process parameters. It was observed that devices show diode
characteristics, however their response to the illumination was quite weak.
Low performance of the devices was discussed in terms of the resistivity and
dopability of the sputtered film. The second part of the thesis deals with the
fabrication and characterization of thin polysilicon films fabricated by e-beam
evaporation. In order to dope the deposited Si films, a very thin boron film
v
was deposited by e-beam evaporation on SiO2 surface thermally grown on a
Si wafer. Then an a-Si was evaporated by the same technique. Samples
were annealed for polysilicon formation by using the technique called solid
phase crystallization (SPC). The annealing was performed in two steps. The
first step was the nucleation part, carried out at 475°C for 8 hours and the second step was the diffusion and crystallization parts that are accomplished at 900°
C for several minutes. The Raman measurements revealed out the crystallinity and grain size. The crystallinity of the polysilicon thin films was also identified by X-Ray diffraction measurements. Finally, the Secondary Ion Mass Spectroscopy (SIMS) analysis was carried out to find out the amount of boron that diffuses into Si film. It was found that a graded boron profile, which is desirable for the solar cell applications, was achieved.
24
Salomon, Ashley. "Oxygen precipitate studies in silicon for gettering in solar cell applications." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/114090.
Повний текст джерелаАнотація:
Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2001.Cataloged from PDF version of thesis.
Includes bibliographical references (page 31).
Oxygen precipitates in silicon can be used (in a process called internal gettering) as sites of heterogeneous nucleation of precipitates of iron and other transition metal that are harmful to solar cell device operation. Oxygen precipitate densities in p- (10¹⁴ boron atoms/cm³) wafers were quantified using chemical etch techniques. The precipitate densities were then used to estimate times to getter iron based on a diffusion limited precipitation model. Oxygen precipitate densities in p++ (10¹⁹ boron atoms/cm³) wafers were quantified using chemical etch techniques. High levels of boron in p++ wafers make quantifying precipitate densities particularly difficult, via etching, or other methods because precipitate densities in highly doped wafers are very high and the size of precipitates small.
by Ashley Salomon.
S.B.
25
Michaud, Amadeo. "III-V / Silicon tandem solar cell grown with molecular beam epitaxy." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS247.
Повний текст джерелаАнотація:
Le photovoltaïque terrestre est actuellement largement dominé par des dispositifs à base de Silicium. La limite théorique d’efficacité de photoconversion pour les cellules solaires en silicium est de l’ordre de 29%. Avec des modules photovoltaïques ayant une efficacité de 26.3% sur le marché, la filière Si est à un niveau de maturité avancée et exploite déjà la quasi-totalité du potentiel de ce genre de cellule solaires. Le travail exposé ici traite d’une autre voie d’amélioration de l’efficacité de conversion des dispositifs photovoltaïques. En effet, les cellules solaires tandem, assemblées en empilant plusieurs cellules permettent de dépasser les limites associées aux cellules Si. La complémentarité importante des cellules solaire III-V avec les cellules Si permettrai en théorie d’atteindre plus de 40% d’efficacité. Cette thèse vise à l’élaboration de cellule III-V performante et compatible avec un usage en tandem. Dans un premier temps, l’épitaxie d’alliages phosphures a été étudiée et en particulier l’influence des conditions de croissance sur le GaInP. Une réduction de la pression en phosphore durant la croissance provoque des modulations de composition au sein de l’alliage. La température a un impact significatif sur la valeur de bande interdite qui diminue en augmentant la température. Des caractérisations de photoluminescence ont permis de définir les conditions optimales de croissance en maximisant le signal de luminescence de l’alliage. L’étude a notamment révélé que cru dans les conditions choisies, le GaInP présente moins de défaut et d’états profonds qu’à plus faibles températures de croissance. Enfin la capacité à atteindre des niveaux de dopages élevés dans l’alliage AlGaInP et l’impact de sa composition sur le dopage ont étés étudié. Dans un second temps, la structure des cellules solaires simple jonction GaInP a été optimisée. Nous illustrons l’impact de la passivation de la surface des cellules par AlInP et AlGaInP, ainsi que l’amélioration du photo-courant par l’amincissement de l’émetteur dopé n. L’introduction de couche non-dopée dans la structure ne permit pas de remédier au problème de collection des porteurs constaté dans les cellules. La couche limitant l’efficacité des cellules est composée de p-GaInP. Des caractérisations par Cathodoluminescence et Fluorescence résolue en temps d’échantillons identiques à cette couche ont été menées. Elles ont mis en avant une faible longueur de diffusion des porteurs générés dans le matériau. La comparaison de ces propriétés avec la littérature et celle mesurées pour GaInP épitaxié par MOCVD, indique que l’amélioration de l’efficacité des cellules passe par une augmentation de la mobilité des porteurs au sein du GaInP. Une solution pratique, combinant GaInP et AlGaAs dans une cellule à hétérojonction a été mise en œuvre. Ce type de structure est une autre perspective intéressante à l’avenir puisque des efficacités à l’état de l’art ont été mesurées. Enfin nous avons développé un procédé permettant d’adapter les cellules pour un usage tandem. Les structures sont crues en inversé puis transférées sur verre ou wafer de silicium sans endommager leur performance. Toutefois, des améliorations sont toujours nécessaires pour permettre l’assemblage d’une cellule tandem fonctionnelle. En effet, la non-planéité introduite par les contacts arrières de la cellule III-V cause actuellement des problèmes de collageTerrestrial photovoltaic is dominated by Silicon based devices. For this type of solar cells, the theory predicts an efficiency limit of 29%. With photovoltaic modules showing 26.6% efficiency already, Silicon-based modules is a mature technology and harvest almost their full potential. In this work, we intend to explore another path toward the enhancement of photovoltaic conversion efficiency. Tandem solar cells that consist in stacking sub-cells, allow to overcome the Si efficiency limit. Since solar cells made of III-V semiconductors are complementary to Silicon solar cells, theory predicts that efficiency above 40% is attainable when combining those types of cells. Here we focus on the elaboration of a performant III-V solar cell, compatible for a tandem use. The first stage of the PhD was to build know-how on phosphide alloys epitaxy with MBE. The influence of the growth conditions on GaInP properties was studied. We noted that composition modulations appear in the alloy when grown with low phosphorus pressure. The growth temperature also impacts the material bandgap, which reduces while increasing the temperature. Photoluminescence characterization served to select the best growth conditions by maximizing the photoluminescence efficiency. We could also highlight that in the conditions chosen, the GaInP exhibits less defect states. AlGaInP alloys are used for passivation purposes in the cells, the influence of the composition of the alloy on the Beryllium doping efficiency was studied. Then GaInP single junction solar cells were fabricated. The different layers composing the cells were optimized. The impact of the front surface passivation with AlGaInP and AlInP was emphasized; improvement of the cell photocurrent by the thinning of the n-doped GaInP layer was also demonstrated. The introduction of a non-intentionally-doped layer in the structure was tested in order to remedy the limits encountered with photocurrent collection. The p-GaInP composing the cells was eventually identified as the limiting factor. In depth characterization of samples mimicking the limiting layer was performed with cathodoluminescence and time-resolved fluorescence. A small diffusion length of the generated carriers was evidenced. Comparison with MOVPE and with literature values suggests that improving the carrier mobility in this layer is the main route to follow for improving of the GaInP cell efficiency. A practical solution was proposed and implemented: we designed a cell combining GaInP and AlGaAs in a heterojunction cell. This structure proves to be very relevant for the project since state of the art photoconversion efficiency of 18.7% was obtained. Finally a process was developed to adapt the III-V solar cells to the tandem configuration. Inverted PV cells structures were grown and transferred on glass or Silicon hosts without degradation of their efficiency. Further improvement of the process is needed to build a full tandem device, in particular the back metallization of the III-V cells must be compatible with the bonding of the cells on the host substrate
26
Naeem, Muddassar. "Exploring possibilities to enhance silicon solar cell efficiency by downconversion of sunlight." Thesis, 2015. http://hdl.handle.net/2440/95229.
Повний текст джерелаАнотація:
Improving the efficiency of solar cells is an active area of research in photovoltaic industry. The research work presented in this dissertation is based on a quest for better and improved silicon solar cells. The current work aims to explore different possibilities by studying advance approaches for PV applications. Additionally this work is intended to seek the feasibility of new photonic concepts for improving silicon solar cells. In this work we have investigated solar downconverters consisting of tellurite glass. Their fabrication process is discussed followed by the experimental characterization. Optical measurements such as absorption spectra, fluorescence spectra and fluorescence quantum efficiency are undertaken. These optical measurements enabled to understand physical processes associated with the materials used. Furthermore, the work presented in the thesis is focused on the realization of a downconverter. The work can be roughly sub-divided into two parts. One part identifies the suitable energy conversion materials and the second part deals with the development and demonstration of the experimental method for characterizing a downconverter. The final part of the work extends investigation for more efficient materials prior to their use at the practical level. We also propose an architectural design for the efficient use of a downconverter with a silicon solar cell.Thesis (M.Phil.) -- University of Adelaide, School of Chemistry and Physics, 2015
27
Kuo, Chao-Ke, and 郭昭克. "Silicon Quantum Dots Solar Cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/05717744469401540780.
Повний текст джерела
28
Wei-Yen, Chen, and 陳緯諺. "Silicon nanorod array solar cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/81322943767633327172.
Повний текст джерелаАнотація:
碩士國立臺灣師範大學
物理學系
98
In this study, solar cells consisting of ordered p-i-n junction silicon nanorod matrix array with different lengths, diameters and period were fabricated. The advantages of p-i-n nanorod structures were low reflection and high surface to volume ratio compared to planar silicon thin films. Moreover, we designed hexagonal arrays to get sufficiently dense array to gain more number of p-i-n junction. The direct electrical pathways provided by the nanorod ensure the rapid collection of carriers generated throughout the device limited primarily by the surface area of the nanrods array. And devices deposit the ITO film would supply a shorter carrier diffusion length to enhance the photocurrent. Finally, we present that the p-i-n nanorod of matrix and hexagonal array structure solar cell actually improve the power conversion efficiency up to 10%, and had an excellent antireflection performance of optical. After depositing the ITO film, it enhances the nanorod devices photocurrent value 18.24% (the highest).
29
Chuang, Yu-Lin, and 莊郁琳. "Silicon Nanohole Arrays Solar Cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/78167806625579841077.
Повний текст джерелаАнотація:
碩士國立臺灣師範大學
物理學系
99
On Earth, solar energy is inexhaustible and non-pollution. Here, we take silicon as the materials for solar cell because of its rich reserves, the advantages of high hardness and high melting point. But, after the light incident into the planar silicon surface, there will be over 30% of them reflected and wasted. Recently, adding nanostructures on silicon surface is proposed. It will significantly reduce reflections, effectively enhance the absorption, and improve the photoelectric current and the energy conversion efficiency. Here, we add nanohole arrays structure on the surface of our solar cells, and that reduced the light reflection and increased the absorption. In addition, these nanohole structures increase the area of the p-n junction and reduce the carrier transport path, that will produce more of the carriers and more carriers are collected. Once photocurrent was increased and thus enhances the energy conversion efficiency of solar cells. The study begins at the comparison of optical reflectivity properties for the various sizes of nanohole arrays, and we discuss the impact of nanohole arrays with different structural parameters. After growing n-layer and fabricating the electrodes of components, we compare the energy conversion efficiency and the external quantum efficiency of the devices which plane structure and with nanohole arrays structure devices, respectively. That is in order to find the optimum structure parameters of silicon solar cells. We find the significantly improved of the energy conversion efficiency and the external quantum efficiency of the devices which were add nanohole arrays on the devices’ surface compare with planar devices. The best energy conversion efficiency is 10.24% and the highest external quantum efficiency is 72.8%.
30
Huang, Hou-ying, and 黃厚穎. "Study of Silicon-Based Solar Cell." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/9n9hv7.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
電子工程系
94
Because petroleum will be used up in this century, it is urgent to find new substitute energy. Because solar energy is clean and almost unlimited, many scientists are working on developing high efficiency and low cost solar cells. Until now, practical solar cells are silicon p-n junction structure. However, efficiency of this structure approaches theoretical limit. In this work, we will first introduce strategies used to improve cells’ performance. We will discuss effect of each part of this cell and expect to optimize it. We also developed a new cell structure using band to band tunneling. Band to band tunneling in this structure generates many carriers even more than photo-generated carriers. Those additional carriers enlarge short circuit current very much. However, the efficiency of the above band-to-band tunneling structure is still smaller than that of conventional structure because output voltage at high output current region is too low. A gate electrode is put upon channel region. This gate voltage can change band in channel region and thus affect band to band tunneling. To cause more band to band tunneling, SiGe which has smaller bandgap is used instead of silicon. As expected, band to band tunneling in SiGe tunneling structure is more prominent and short circuit current becomes larger. However, open circuit voltage is smaller in SiGe tunneling structure. So the resultant efficiency is lower than that for the Si tunneling and the conventional structures. We will discuss effects of doping concentration, mole fraction, shallow junction and gate voltage in tunneling structure. Finally, we will discuss lateral structure. This structure doesn’t help to improve cell performance but this structure is easy to be integrated with IC process. It is also easy for this structure to be connected in series to enlarge output voltage. We will discuss effects of channel length, thickness, and shallow junction.
31
Wei, Tung-Tun, and 魏銅盾. "Fabrication of Amorphous silicon/Single crystalline silicon Heterojunction Solar Cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70812512798816695414.
Повний текст джерела
32
Wu, Chin-Yu, and 吳金祐. "Simulation Study of Amorphous Silicon / Microcrystalline Silicon Tandem Solar Cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/46528516610721379596.
Повний текст джерелаАнотація:
碩士國立中興大學
電機工程學系所
98
In order to establish the simulated model of the Amorphous Silicon Solar Cell, the Microcrystalline Silicon Solar Cell and the Amorphous/Microcrystalline Silicon Tandem Solar Cell, Silvaco TCAD simulated software combined with the real data of the ITRI Solar Cells is used in this study. Base on these Solar Cells models having the same outputted characteristics as the real Solar Cells, the influence and the variation of the Solar Cell characteristics are observed. Firstly, for the study of the Amorphous Silicon Solar Cell and the Microcrystalline Silicon Solar Cell, the thickness, the doping concentration and the density of states of the P-I-N Solar Cells are changed. The related affect and characteristics from the experimental data of the study are understood. Finally, the study focuses on the Amorphous/Microcrystalline Silicon Tandem Solar Cell, whose energy gap and the thickness of the absorptive layer are changed. The best energy gap and the best thickness of the absorptive layer of the Tandem Solar Cell from the variation data of the conversion efficiency of the Tandem Solar Cell are obtained.
33
Fu-ChinYang and 楊富欽. "Tandem solar cell with TCO structure of amorphous and microcrystalline silicon solar cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53237792001475295985.
Повний текст джерелаАнотація:
碩士國立成功大學
光電科學與工程研究所
98
The topic of this research is silicon film deposited at low temperature based on Laser-assisted Plasma-Enhanced Chemical Vapor Deposition system (LAPECVD) to become amorphous and microcrystal silicon film. Because of specially high absorption of silane to CO2 laser, laser beam is guided into chamber during deposition of silicon film to form p-type, intrinsic and n-type silicon film at low temperature, and further investigate the porosity、optical and electrical property、quality of crystallization based on varying laser power assistance. As to application, amorphous silicon is very suitable to form solar cell because of ultra high absorption coefficient compared to single-crystal silicon. However, amorphous silicon would degrade at a longer term luminance. Therefore, the LAPECVD system could supply better quality of silicon thin film to overcome this weakness. This research fabricated solar cell under laser assistance, for efficiency of solar cell without laser assistance is 6.04%, 7.01% for laser assistant solar cell, and final efficiency is up to 7.13% for tandem solar cell. In conclusion, laser assistance technology is benefit for enhance efficiency of solar cell.
34
Ku, Lun-Yu, and 古崙佑. "Crack Analysis of Silicon Solar Cell Module." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/t9h5n3.
Повний текст джерелаАнотація:
碩士元智大學
光電工程學系
105
This paper analyzes the fluorescent emission from the Ethylene Vinyl Acetate （EVA）, which used to be the solar module encapsulation material. By detecting the fluorescent area and spectrum, the position of the cell cracks could be found. In the first part of this study, the EVA sample placed under the sun illumination, UV irradiation, hot environment, pure oxygen situation. We used the monochromator and photoluminescence spectrometer to analyze the transmission, reflection, absorption, and fluorescent spectrum to deduce the aging of EVA. In the second part of this study, we continue to investigate the aged EVA in the solar module by the photoluminescence spectrometer. While crack happened inside module, the fluorescent spectrum would be changed. It was a good approach to apply as a measurement for the position and size of cracks inside module. In addition, how long of existed crack could also be assumed by non-fluorescent area. Key words: EVA, fluorescence, solar module, crack detection.
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Liao, Shih-Ting, and 廖士霆. "Silicon Solar Cell Fabrication and Characteristics Analysis." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/28393961002785774280.
Повний текст джерела
36
Lin, Chia-Te, and 林佳德. "Hydrogen Passivation of Crystalline Silicon Solar Cell." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/31178641818228803238.
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葉雲源. "A Study of Silicon Tandem Solar Cell." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/03955949104457967228.
Повний текст джерелаАнотація:
碩士建國科技大學
電機工程系暨研究所
101
The hydrogenated amorphous Silicon(a-Si:H) and Microcrystalline Silicon thin film solar cell are prepared on ITO glass substrate by electron cyclotron resonance chemical vapor deposition(ECR CVD) system. The optoelectronic characteristics of uc-Si:H deposited by different conditions were analyzed for tandem solar cell. Energy gap of the intrinsic uc-Si:H layer, deposited with SiH4 and H2(the dilution SiH4/SiH4+H2 is 10%) at substrate temperature is 250 ℃ and microwave power is 500 W, is 1.18 eV. Measure the microcrystalline silicon solar cell efficiency of the p-i-n structure by the AM1.5 standard light source, the i-layer on solar cell oper circuit voltage(Voc), short-circuit current(Jsc), fill factor(FF) and energy conversion efficiency(η) have been investigated. The optimized uc-Si:H thin film solar cell with i-layer thickness 1600 nm was found to have Voc is 0.32 V, Jsc is 5.12 mA/cm2, FF(%) is 42.03, η is0.69 %. After carrying on Tandem, Tandem Solar Cell have Voc is 0.96 V, Jsc is 13.9 mA/cm2, FF(%) is 64.82, η is 7.41 %.
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Lane, Shave-Young, and 連水養. "fabrication of single crystal silicon solar cell." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/23406980987802311505.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
電機工程系碩士班
91
Solar cell is one of renewable energy that is expected to alternate a part of conventional fossil energy. The problem of the solar cells is in its high manufacturing cost, and therefore generalization of solar cell is still restricted now. In order to generalize the solar cell, a low cost fabrication process is demanded. In this study, we proposed a new fabrication process for solar cells where all the vacuum process is substituted by coating method. Both the deposition of Phosphate dopant source for diffusion on the p-type wafer and the deposition of anti-reflection film are achieved by SOG(spin on glass) coating method which is developed in this study. As for the coating of anti reflection coating, TiO2 sols are developed. After coating and annealing the film on Si film at 900oC, we obtained high purity TiO2 films with refractive index of 2.2, atomic ratio of Ti:O =1:1.867, and C concentration of 0.03atom%. The Si wafer coated with TiO2 film showed a low reflectivity of as low as 4%. These results show the feasibility of the developed antireflection coating technology. As for the forming of p-n junction, we developed the phosphate doped solgel dopant source for thermal diffusion. After coating the solgel on p type Si wafer and successive 900oC annealing, p-n junction was formed successfully. The fabricated p-n junction diode shows the Vth of 0.55 volt, ideality factor of 1.16. These results show the feasibility of the proposed method. This study provided a possibility to realize a new fabrication process for achieving low cost solar cells.
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Liu, Wei-Lin, and 劉威麟. "Modeling of Amorphous Silicon Tandem Solar Cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/84535374286527263749.
Повний текст джерелаАнотація:
碩士國立交通大學
光電系統研究所
99
Due to the depletion of energy resources, alternative energy development is the trend of the future. There are many alternative energy sources, and the solar power is a clean, environmentally friendly, renewable and inexhaustible one among them. Among several types of solar cells that are currently with high attention, we chose the amorphous silicon thin-film solar cells for the subject. Thin-film solar cells can be produced on the substrates which could use inexpensive glass, plastics, ceramics, graphite, or metal, and the film only needs a few μm to produce photo-generated voltages. So under the same light-receiving area, thin-film solar cell can significantly use less amount of raw materials than the conventional silicon solar cell. One of the important characteristics of thin film solar cells is flexibility. Its flexible properties can be applied to a wide variety of surfaces even combined with the building and window. Amorphous silicon thin-film solar cell does not surpass its crystalline counterpart for high efficiency. But due to severaladvantages such as mature manufacturing process, flexibility, and combined with the building materials, the amorphous silicon solar cell research is still very popular. This research is focused on features which are different from other solar cells. One is the band tail structure of amorphous silicon materials, and the other is surface roughness. By studying the band tail physical model, we can devise the band tail absorption by tuning its parameters. And another topic is the surface roughness. We create two different surface roughness of the structure. First we use haze formula to simulate the flat structure with haze by ideal situation. On the other hand, we established the real textured surface for simulating in order to achieve the real situation. Finally, we combine the surface roughness and band tail in our simulation structure, and fitting the simulation results to the experimental data to enhance the simulation accuracy. Combination of these two features on a commercially available software is very important to expand our research for greater use. The accuracy of the simulation verified by the fitting process can ensure the validity of our band tail model and texture interface. We hope this application can be useful for design of the next generation thin film solar cell.
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Ching, Liang-Hao, and 晉良豪. "Silicon based tandem thin film solar cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/50648944921647646627.
Повний текст джерелаАнотація:
碩士國立交通大學
光電工程學系
100
We have fabricated silicon-based alloy tandem thin film solar cell by using high density plasma method. And optimize the tandem thin film solar by using tunneling-recombination junction and high hydrogen ratio bottom absorption layer. Due to high optical band gap of amorphous silicon thin film, a-Si thin film solar cell shows the property of high open circuit voltage. But, this feature also limit the absorption in the near infrared part of solar spectra, so the short circuit current density is much lower compared with amorphous silicon germanium alloy thin film silicon solar cell. In order to overcome the above-mentioned shortcomings, we utilize the amorphous silicon germanium alloy a-SiGe (band gap 1.4~1.6eV) to engineer the optical bandgap. The thin films with different optical bandgap could absorb the different part in solar spectra. Thus, we can effectively take advantage of the full solar spectra. And we can also develop muti-junction thin film solar cell based in the thin film solar cells. Each junctions of muti-junction solar cell have different optical bandgap, so they could absorb different part of solar spectra. Currently, we have demonstrated single junction a-Si, a-SiGe thin film solar cell with conversion efficiency achieving 9.2% and 5.7%, respectively. Compared with a-si thin film solar cell, the quantum efficiency of a-SiGe significantly increased in 650~800nm. Besides, we have also demonstrated double junctions solar cell, including a-Si/a-Si and a-Si/a-SiGe tandem solar cell. The open circuit voltage of a-Si/a-Si, a-Si/a-SiGe tandem solar cells is 1.69V, 1.46V respectively. The muti-junction we mentioned above have successful performance in open circuit voltage. Conversion efficiency of a-Si/a-Si and a-Si/a-SiGe tandem solar cell is 8.8% and 6.3% respectively. In the future, my research will focus on tunneling junction between each interface and film quality of each kind silicon based alloy to obtain the triple-junction thin film solar cell with high conversion efficiency.
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Chen, Chih-Wei, and 陳志偉. "Improved single-crystal silicon solar cell electrode." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/40607447311459423923.
Повний текст джерелаАнотація:
碩士國立勤益科技大學
機械工程系
98
This study used a sol-gel solution containing phosphorus as the phosphorus diffusion source, which was applied onto single-crystal silicon wafers through spin coating method. In this basic conditions, optoelectronic property analysis is different electrode structures and materials for solar cells. The study aims to explore the effect of different structures of silver and ITO film were used as electrodes on single crystal silicon solar cells. Structures can be divided into ITO、silver 、silver covered in ITO、ITO covered in silver、thermal treatment ITO、thermal treatment silver、thermal treatment silver covered in ITO and thermal treatment ITO covered in silver. Different transparent conductive material (transparent conductive oxide, TCO), such as ITO (indium tin oxide, referred to as ITO), indium zinc oxide (indium zinc oxide, referred to as IZO) instead of the traditional single-crystal silicon solar cell silver wire electrodes. The UV/Vis instrument was used in this study to measure the transmittance of TCO. The α-step instrument was measurement the thickness of the film thickness, using Four-Point Probe to measure the sheet resistor of TCO films. The different metal such as metal of Ag, Al, Cu, Pt and Ti covered in between the silicon and the TCO film can expect to successfully export the electrons to increase solar cell conversion efficiency. The film of metal covering the silicon wafer will be reduce the light entering, and the transmittance of thin metal films will be important to control. Analysis Solar cell is the use of solar light simulator to measure the light current-voltage curve, thus obtained solar cell open circuit voltage, short circuit current, fill factor and the photoelectric conversion efficiency. Analysis of dark current curve used in this study was reverse saturation current, series resistance, shunt resistance and on/off ratio. To compare these features with solar features, analysis of diode characteristics on the impact of solar cells.
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Jin, Hao. "Characterization of silicon / silicon dioxide / LPCVD silicon nitride stacks for solar cell application." Phd thesis, 2007. http://hdl.handle.net/1885/147115.
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蘇明皓. "Life Cycle Assessment for Polycrystalline Silicon and Amorphous Silicon Solar Cell." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/46413921625782876309.
Повний текст джерелаАнотація:
碩士國立交通大學
工學院碩士在職專班永續環境科技組
98
This research which is applied with the life cycle appraisal technology is used the life cycle DoItPro software and Eco-indicator 95 as the environment impact appraisal pattern to quantify the environment impact which grows in the manufacture and the operational phase of the Polycrystalline silicon and a-Si thin film solar cell. To make a questioning analysis on the energy, the material, the air pollutant, the water pollutant, and the waste and calculate the environment impact of various stages, then, compares the environment impact differences of the two kind solar energy products. By the study results we can find that main environment impact on the solar cell manufacture stage are energy and water resources consumption. To produce 1kWp a-Si thin film solar cell need to consume 7,940MJ energy and 3,918 Kg water resources, otherwise, make 1 kWp Polycrystalline silicon solar cell need to consume 4,446 MJ energy and 2,226 Kg water resources. The environment impact of the solar cell operational phase is forward, to reduce energy consumption and the global warming are the major objectives. By the 20 year service life statistics, 1 kWp a-Si thin film solar cell may produce 3,589,49 MJ energy and reduce 20.9 tons CO2 emissions, otherwise, 1 kWp Polycrystalline silicon solar cell may produce 326,408 MJ energy and reduce 19 tons CO2 emissions. The appraisal result of total life cycle showed that the solar cell operational phase energy is higher more than the energy of manufacture stage consumption. From raw material to the product operational phase, 1 kWp a-Si thin film solar cell may produce 351,010 MJ energy and the multi-crystal silicon solar cell may produce 321,962 MJ energy, which are really contribution for energy reduction.
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Chen, Chun-Liang, and 陳俊良. "Deposition of Silicon Oxide at Front Side of Silicon Solar Cell." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/tca2qj.
Повний текст джерела
45
Greer, Michael R. "A 6% efficient MIS particulate silicon solar cell." Thesis, 1998. http://hdl.handle.net/1957/34037.
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46
Sun, Chih-chung, and 孫志中. "Simulation and optimization of Heterojuction silicon solar cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/6pw6zq.
Повний текст джерелаАнотація:
碩士明道大學
材料科學與工程學系碩士班
98
Technology CAD (Technology Computer Aided Design, or TCAD) is a branch of electronic design automation that model semiconductor fabrication and semiconductor device operation. A computer model for a simulation of heterojunction (HJ) solar cells based on a variety of physical model is discussed. In this article, by means of modeling and numerical computer simulation, the influence of n+-layer concentration, n+-layer thickness, c-Si concentration, c-Si thickness, p+-layer concentration, p+-layer thickness, front contact width, Shockley–Read–Hall (SRH) lifetime on the solar cell performance is investigated. The simulation performance of silicon-based solar cell including open circuit voltaic (Voc), short circuit current density (Jsc), fill factor (FF), efficiency (?? is observed. This study improves the understanding of this device and to derive arguments for design optimization. After optimizing the simulation parameters, the silicon-base solar cell with efficiency over 21% was obtained by TCAD simulation technology.
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Huang, Shin-Yu, and 黃信淯. "Decision analysis of crystalline silicon solar cell substitution." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/80159814601263275264.
Повний текст джерелаАнотація:
碩士元智大學
工業工程與管理學系
99
With the shortage of energy, clean and renewable energy becomes a popular research topic. Solar energy is one of the important alternatives. However, there exists optical cell recombination loss and mismatch loss in electricity during the manufacturing and packaging processes of solar modules. These two types of losses would decrease the conversion efficiency of solar modules, and directly reduce the profit of solar module packaging manufacturers. This research studies electrical power output of modules to find the best supplier of crystalline silicon solar cells by investigating their replaceable relationship. The objective of this research is to analyze the similarity of power output of the modules that use the solar cells from different suppliers. Analysis of variance (ANOVA) is first applied to test whether the power output of solar cells are significantly different. If consistency is rejected, Tukey test is then conducted for pairwise comparisons. Under the disturbance of recombination loss and mismatch loss, power input and output are imbalanced which leads to different level of loss in efficiency after module packaging. This research investigates the solar cells with no difference in power output by multiple comparisons and sets up the rule for cell replacement. The results show that the proposed criteria of supplier selection can reduce cost, increase profit, and improve the competitive performance of solar module packaging manufacturers.
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Liu, Tse-Hsiao, and 劉哲孝. "Study of Trap Influence on Silicon Solar Cell." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/81829154644837534144.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
電子工程系
96
High-efficiency, inexpensive solar cells are required in order to economically compete with conventional energy sources such as fossil and petroleum fuels. Silicon is one of the most abundant elements in the earth’s crust. Using solar energy as a substitute for conventional energies is a dream, but it is possible to make the dream come true by developing Si solar cell technology. The most important optical property of material in solar cell design is its optical absorption properties, which determine electron-hole pair creation ability. It was reported that amorphous silicon has high optical absorption. Unfortunately, most of the carriers annihilate via defect-assisted recombinations due to long paths in the a-Si. On the other hand, crystalline silicon is a candidate material for the fabrication of high-efficiency, inexpensive solar cells. Unfortunately, an inherent disadvantage of low infrared absorption in single crystal silicon essentially limits the performance of single crystal silicon cells. In order to improve the efficiency of single crystalline solar cell, the metallic impurities are employed in c-Si solar cell. In this thesis, the effect of impurity traps for efficiency improvement of solar cells will investigated by MEDCI simulation. Firstly, we will introduce strategies used to improve cells’ performance and discuss effect of each part of this cell and expect to optimize it. Next, the traps of metallic impurities dope in the proper position, which generate many photo-generated carriers. Hence, the short circuit current of the solar cell with traps is not clear larger than conventional solar cell, because the recombination rate is also higher in trap region. Though the short circuit current does not increase clearly, the open circuit voltage of the solar cell with traps is much lager than conventional solar cell, because the dark current is blocked when it pass through the trap region. We will discuss effects of trap concentration, trap level, trap region depth, length and location to observe solar cell performance. Finally, we will discuss lateral structure. This structure is easy to be integrated with IC process. It is also easy for this structure to be connected in series to enlarge output voltage. We’ll utilize various trap level of impurity traps with different position and width in i-layer to observe solar cell performance by some physical phenomenon.
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Ku, Chun-Lun, and 辜俊倫. "Antireflection and Solar Cell Application of Nanostructured Silicon." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/83734415296980928649.
Повний текст джерелаАнотація:
碩士國立臺灣海洋大學
光電科學研究所
93
We have studied the anti-reflection property of two silicon nanostructures: the nanotips and the nanowires fabricated through self masked dry etching(SMDE) and electroless metal deposition etching(EMDE), respectively. Simple solar cells based on the two structures were also successfully demonstrated. The etching rate of EMDE was found to be 40 times faster than that of SMDE. Both the two structures show broadband antireflection properties, with the nanotips’ performance be better due to the equilibrium graded index of the structure.. The antireflection performance of nanotips is better for their acting as equivalent graded index, which have been verified using the finite different time domain method. After boron diffusion for fabrication of solar cells, apparent structural damages on both nano-structures were observed. Nevertheless, the reflectivities of both nano-structures after diffusion were still lower than that of pure silicon wafer. The efficiency of the solar cells thus fabricated on silicon nanowires and nanotips showed two fold and four fold enhancement respectively, as compared to that of solar cells fabricated on pure silicon wafer. However, the efficiency and fill factors of solar cells thus fabricated were still far from perfect, due to the still simple structure as well as the high serial resistance of the solar cells, requiring further improvement in the future.
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Tsai, Ming-Ying, and 蔡明彥. "Fabricated the selective emitter polycrystalline silicon solar cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/62438469921903760560.
Повний текст джерелаАнотація:
碩士國立中興大學
材料科學與工程學系所
99
Abstract This thesis presents a simple process to fabricate solar cell with a selective emitter by using a phosphorus doped Ag paste. To fabricated poly-Si solar cells, the surface-textured p-type poly-silicon wafers were used as substrates. The n-type poly-Si layers with two different sheet resistances, 60 and 100 ohm, had been fabricated at high temperature furnace. A silicon nitride film was deposited onto front side of poly-Si wafer as anti-reflection layer through a plasma-enhanced chemical vapor deposition. Finally, the front- and back-side electrodes were screen-printed with Ag and Al pastes, respectively. In order to form the selective emitter structure, a self-alignment screen-printing and one step co-firing diffusion techniques were used with novel Ag:P paste (Ag paste mixed with P2O5). Comparing with the standard sample, the cell performances of the 60ohm poly-Si wafers with a selective emitter were improved with short-current density (Jsc) of 0.01 A/cm2, fill-factor (FF) of 8%, serial resistance (Rs) of 0.17ohm, and efficiency of 2.4%. The better cell with 100-ohm poly-Si wafers with a selective emitter had the improvements of Jsc of 0.03 A/cm2, FF of 1.8 % Rs of 0.09ohm, and efficiency of 1.4 %, compared with the standard sample. Moreover, the open-voltages (Voc) values of both poly-Si solar cells with and without selective emitter are 0.57 V. After a series of cell characteristics, we found that the Voc values of cell with selective emitter are larger than standard cell. Measuring under a 480 to 600 nm incident light, the different Voc values of 0.28 V and 0.32 V were found from cell with and without selective emitter, respectively. This result may be caused by the intensity of a separated incident light is too low to reduce the open-voltage of the poly-Si solar cell. Smaller Voc values were measured when the wavelength of incident light was smaller than 480 nm. For external quantum efficiency (EQE) measurement, the peak efficiency value is occurred at 360 nm. The EQE values of 54 % (standard cell) and 75 % (elective emitter) were measured. In addition, the solar cell with selective emitter shows better Voc and efficiency than standard cell in short-wavelength range. Finally, poly-Si solar cell properties such as conversional efficiency, open-voltage, short-current and fill-factor were observed under both continuous and flash solar photovoltaic measurement modes. It was found that the cell performances measured under flash mode show the better values in electric and yield. This result might due to the thermal heat effect to reduce the performance and efficiency of the poly-Si solar cell.