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Judkins, Zachara Steele. "A market analysis for high efficiency multi-junction solar cells grown on SiGe." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42143.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.Includes bibliographical references (leaves 50-53).
Applications, markets and a cost model are presented for III-V multi-junction solar cells built on compositionally graded SiGe buffer layers currently being developed by professors Steven Ringell of Ohio State University and Eugene Fitzgerald of MIT. Potential markets are similar to those currently occupied by high efficiency multi-junction space solar cells grown on a Germanium substrate. Initial cost analysis shows that at production volumes similar to those of the state of the art, cost could be reduced by a factor of' four. Significant market share may be gained in both the space and terrestrial PV markets due to improved performance associated with superior materials properties advantages as well as production cost reductions.
by Zachary Steele Judkins.
M.Eng.
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Polyzoeva, Evelina Aleksandrova. "Tradeoffs of the use of SiGe buffer layers in tandem GaAsP/Si solar cells." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107289.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 101-103).
III-V multi-junction solar cells currently have the highest reported theoretical and experimental energy conversion efficiency but their cost, mainly attributed to the use of expensive substrates, limits their widespread use for terrestrial applications. Successful integration of III--V's on a Si substrate to enable a III-V/Si tandem cell can lower the cost of energy by combining the high-efficiency of the III--V materials with the low-cost and abundance of the Si substrate. A maximum theoretical efficiency of 44.8% from a tandem cell on Si can be achieved by using a GaAsP (Eg=1.7 eV) as the top cell. Out of several possible integration routes, the use of a linearly graded SiGe buffer as interfacial layer between the two cells potentially yields the highest quality for the epitaxial GaAsP layer, an essential requirement for realization of high-efficiency solar cells. In this thesis, the impact of the SiGe buffer layer on the optical and electrical characteristics of the bottom Si cell of a GaAsP/Si tandem solar cell was assessed via experimental work. The growth of a SiGe buffer layer was shown to increase the threading dislocation density and as a result the leakage current of the bottom Si cell by about 10x. In addition, the low-bandgap SiGe absorbs more than 80% of the light that is intended for the Si sub-cell, reducing the short-circuit current of the Si cell from 33 mA/cm² to only 6 mA/cm². By using a step-cell design, in which the SiGe was partially etched to allow more light to reach the bottom cell, the current was increased to 20 mA/cm². To quantify the merits of the studied approach as well as evaluate other approaches, we have carried out a theoretical study of absorbed irradiance in a Si single-junction cell, a bonded GaAsP/Si tandem cell, a GaAsP/SiGe/Si tandem cell as well as the step-cell design. The GaAsP/Si bonded tandem cell showed 24% relative improvement in light absorption over a single-junction Si cell. The addition of a SiGe graded buffer was shown to reduce the total absorption by 25%, bringing the efficiency of GaAsP/SiGe/Si tandem cell under that of the Si single-junction cell. The step-cell design, even though successful in increasing light absorption, was not found effective in achieving a higher absorbed power density than that of the Si cell. These results suggest that any future work on integrating GaAsP cells on Si towards a high-performance tandem cell should be focused on using a higher-bandgap material as a graded buffer or using a wafer bonding technique.
by Evelina Aleksandrova Polyzoeva.
Ph. D.
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Sharma, Prithu. "Integration of GaAsP alloys on SiGe virtual substrates for Si-based dual-junction solar cells." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/88367.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 117-122).
Integration of III-V compound semiconductors with silicon is an area that has generated a lot of interest because III-V materials and Si are best suited for different types of devices. Monolithic integration enables the best material to be chosen for each application, enabling new functionalities with the potential of additional miniaturization on a system level. Integration of GaAsP alloys on Si substrates would enable the creation of high efficiency dual-junction solar cells on low cost and light weight Si wafers and would also enable a path for yellow and green light emission devices on a Si platform. Our work focused on the materials integration problems for multiple pathways to integrate GaAsP alloys on Si substrates. We first addressed the direct integration of GaAsP alloys on Si substrates. Our results showed that despite the low lattice-mismatch conditions at the P-rich end of the GaAsP alloy spectrum, it was difficult to achieve thin films low defect density. We proceeded to focus on the integration of GaAsP alloys on Si via the use of SiGe compositionally graded layers. Through a combination of methods we addressed problems related to antiphase disorder and lattice mismatch between GaAsP and SiGe materials system. We demonstrated the epitaxial growth lattice-matched GaAsP on Si₀.₈₈Ge₀.₁₂, Si₀.₅Ge₀.₅, Si₀.₄Ge₀.₆ and Si₀.₃Ge₀.₇ virtual substrates with excellent interface properties. Our studies showed the effects of initiation conditions and intentional strain at the GaAsP/SiGe heterovalent interface. We have established strain-engineering methods at the GaAsP/SiGe heterovalent interface to prevent dislocation loop nucleation and expansion. We were able to attain GaAsP films on Si with a threading dislocation density as low as 1.2x10⁶/cm² . Our GaAsP/SiGe heterovalent interface research advanced the understanding of such structures. We developed methods to fabricate optimized GaAsP tunnel junction film, which would be necessary for any current-matched dual junction solar cell design. Prototype dual-junction GaAsP/Si solar cell test devices showed good preliminary performance characteristics and offer great promise for future devices integrated with the newly developed high quality GaAsP/Si virtual substrates.
by Prithu Sharma.
Ph. D.
4
Andre, Carrie L. "III-V semiconductors on SiGe substrates for multi-junction photovoltaics." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1100290985.
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Kraft, Achim [Verfasser], and Holger [Akademischer Betreuer] Reinecke. "Plated copper front side metallization on printed seed-layers for silicon solar cells." Freiburg : Universität, 2015. http://d-nb.info/111945252X/34.
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Martin, de Nicolas Silvia. "a-Si : H/c-Si heterojunction solar cells : back side assessment and improvement." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112253/document.
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Parmi les technologies photovoltaïques à base de silicium, les cellules solaires à hétérojonction a-Si:H/c-Si (HJ) ont montré une attention croissante en ce qui concerne leur fort potentiel d’amélioration du rendement et de la réduction de coûts. Dans cette thèse, des investigations sur les cellules solaires à hétérojonction a-Si:H/c-Si de type (n) développées à l'Institut National de l'Énergie Solaire sont présentées. Les aspects technologiques et physiques du dispositif à HJ ont été revus, en mettant l'accent sur la compréhension du rôle joué par la face arrière. À travers le développement et la mise en œuvre des films de a-Si:H intrinsèques et dopés (n) de haute qualité des cellules solaires à HJ, les conditions requises en face arrière des dispositifs ont été établies. Une comparaison entre plusieurs types de champ surface arrière, avec et sans l’introduction d’une couche buffer, est présentée et les caractéristiques des cellules solaires résultants sont discutées. Une discussion autour du contact arrière de cellules solaires à HJ est aussi présentée. Une nouvelle approche d’oxyde transparent conducteur en face arrière basé sur les couches d’oxyde de zinc dopé au bore (ZnO:B) est étudié. Dans le but de développer des couches de ZnO:B de haute qualité bien adaptées à leur utilisation dans des dispositifs à HJ, différents paramètres de dépôt ainsi que des traitements après dépôt comme le post plasma d’hydrogène ou le recuit laser sont étudiés et leur influence sur des cellules solaires est évaluée. Au cours de ce travail il est montré que la face arrière des cellules solaires à HJ joue un rôle important sur l’accomplissement de hauts rendements. Cependant, l'augmentation de la performance globale du dispositif dû à l’optimisation de la face arrière de la cellule est toujours dépendante des phénomènes ayant lieu en face avant des dispositifs. L'utilisation des films optimisés pour la face arrière des HJs développées dans cette thèse, associée à des couches améliorées pour la face avant et une nouvelle approche de métallisation nous a permis d’atteindre un rendement de conversion record de plus de 22%, démontrant ainsi le grand potentiel de cette technologie à HJ de a-Si:H/c-SiAmongst available silicon-based photovoltaic technologies, a-Si:H/c-Si heterojunctions (HJ) have raised growing attention because of their potential for further efficiency improvement and cost reduction. In this thesis, research on n-type a-Si:H/c-Si heterojunction solar cells developed at the Institute National de l’Énergie Solaire is presented. Technological and physical aspects of HJ devices are reviewed, with the focus on the comprehension of the back side role. Then, an extensive work to optimise amorphous layers used at the rear side of our devices as well as back contact films is addressed. Through the development and implementation of high-quality intrinsic and n-doped a-Si:H films on HJ solar cells, the needed requirements at the back side of devices are established. A comparison between different back surface fields (BSF) with and without the inclusion of a buffer layer is presented and resulting solar cell output characteristics are discussed. A discussion on the back contact of HJ solar cells is also presented. A new back TCO approach based on boron-doped zinc oxide (ZnO:B) layers is studied. With the aim of developing high-quality ZnO:B layers well-adapted to their use in HJ devices, different deposition parameters as well as post-deposition treatments such as post-hydrogen plasma or excimer laser annealing are studied, and their influence on solar cells is assessed. Throughout this work it is evidenced that the back side of HJ solar cells plays an important role on the achievement of high efficiencies. However, the enhancement of the overall device performance due to the back side optimisation is always dependent on phenomena taking place at the front side of devices. The use of the optimised back side layers developed in this thesis, together with improved front side layers and a novel metallisation approach have permitted a record conversion efficiency over 22%, thus demonstrating the great potential of this technology
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Cousins, Michael Andrew. "Microstructure of absorber layers in CdTe/Cds solar cells." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/4266/.
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This work concerns the microstructure of CSS-grown CdTe layers used for CdTe/CdS solar cells. Particular attention is given to how the development of microstructure on annealing with CdCl(_2) may correlate with increases in efficiency. By annealing pressed pellets of bulk CdTe powder, it is shown that microstructural change does occur on heating the material, enhanced by the inclusion of CdCl(_2) flux. However, the temperature required to cause significant effects is demonstrated to be higher than that at which heavy oxidation takes place. The dynamics of this oxidation are also examined. To investigate microstructural evolution in thin-films of CdTe, bi-layers of CdTe and CdS are examined by bevelling, thus revealing the microstructure to within ~1 µm of the interface. This allows optical microscopy and subsequent image analysis of grain structure. The work shows that the grain- size, which is well described by the Rayleigh distribution, varies linearly throughout the layer, but is invariant under CdCl(_2) treatment. Electrical measurements on these bi-layers, however, showed increased efficiency, as is widely reported. This demonstrates that the efficiency of these devices is not dictated by the bulk microstructure. Further, the region within 1 µm of the interface, of similar bi-layers to above, is examined by plan-view TEM. This reveals five-fold grain-growth on CdCl(_2) treatment. Moreover, these grains show a considerably smaller grain size than expected from extrapolating the linear trend in the bulk. These observations are explained in terms of the pinning of the CdTe grain size to the underlying CdS, and the small grain size this causes. A simple model was proposed for a link between the grain-growth to the efficiency improvement. The study also examines the behaviour of defects within grains upon CdCl(_2) treatment provided the first direct evidence of recovery on CdCl(_2) treatment in this system. Finally, a computer model is presented to describe the evolution of microstructure during growth. This is shown to be capable of reproducing the observed variation in grain size, but its strict physical accuracy is questioned.
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Bartsch, Jonas [Verfasser]. "Advanced Front Side Metallization for Crystalline Silicon Solar Cells with Electrochemical Techniques / Jonas Bartsch." München : Verlag Dr. Hut, 2012. http://d-nb.info/1020298839/34.
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Benick, Jan [Verfasser]. "High-Efficiency n-Type Solar Cells with a Front Side Boron Emitter / Jan Benick." München : Verlag Dr. Hut, 2011. http://d-nb.info/1013526287/34.
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Gonzalez, Maria. "Electronic Defects of III-V Compound Semiconductor Materials Grown on Metamorphic SiGe Substrates for Photovoltaic Applications." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250703650.
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Dauwe, Stefan. "Low temperature surface passivation of crystalline silicon and its application to the rear side of solar cells." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971903530.
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Kranz, Christopher [Verfasser]. "Analysis and modeling of the rear side of industrial-type passivated emitter and rear silicon solar cells / Christopher Kranz." Hannover : Technische Informationsbibliothek (TIB), 2017. http://d-nb.info/1127248782/34.
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Hasan, Mahmudul. "Rear side BSF/emitter patterning of SHJ-IBC solar cells using selective deposition and hydrogen plasma etching of a-Si:H." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-198191.
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Silicon heterojunction interdigitated back-contact (SHJ-IBC) solar cells have attracted considerable attention because of their potential to achieve very highly efficiency. However, the back contacting scheme leads to additional fabrication complexity mainly resulting from the formation of interdigitated n- (back surface field (BSF)) and p-type (emitter) hydrogenated amorphous silicon (aSi:H) strips. Photolithography is widely used for patterning of the interdigitated strips, but this is a costly and impractical technique for industrial applications. This work focuses on the development of simple BSF/emitter patterning approaches of SHJ-IBC cells to replace photolithography and two methods, selective deposition (SD) and dry etching of a-Si:H, have been evaluated. Selective deposition of materials is a promising approach for electronic device fabrication, which allows materials deposition on pre-defined areas while no deposition occurs on other parts of the device. As a result, costly lithography and etching steps can be avoided. Selective deposition of a-Si:H at low temperature (~200C) using plasma-enhanced chemical vapor deposition (PECVD) technique, is a novel approach for rear side emitter patterning of SHJ-IBC solar cells. The first target of this study was to selectively deposit a-Si:H on crystalline silicon (c-Si) while avoiding deposition on the SiOx mask. The second target was to achieve a sufficient quality a-Si:H/c-Si interface passivation using selectively deposited silicon film. The SD of a-Si:H was realized by short deposition of a-Si:H followed by etching using hydrogen plasma. Hydrogen atoms can selectively eliminate strained bonds in a-Si:H films. Proper hydrogen plasma exposure allows to discriminate between Si-Si bonds on different substrates. As such, substrate-SD of a-Si:H is possible. Repetition of short deposition followed by hydrogen plasma etching leads to net deposition on one substrate, i.e., c-Si, but not on mask layers, i.e., SiOx. Two deposition approaches were used to develop SD. The first approach is "Time-modulated power"; where deposition and etching is controlled by radio frequency power. The second deposition approach is "Time-modulated SiH4", where film deposition and etching is controlled by pulsed SiH4 flow. Spectroscopic Ellipsometry (SE) and Transmission Electron Microscopy (TEM) were utilized to measure selectivity, film thickness, and morphology. Effective carrier lifetime (τeff) was measured to check the c-Si surface passivation quality using Quasi-steady-state photo-conductance (QSSPC) method and Photoluminescence (PL) image. From TEM it was observed that, although selectivity is achieved in this work, crystallization of the deposited Si film on c-Si results in poor passivation quality, which is probably induced by long hydrogen plasma exposure. To reduce the crystallization rate, NF3 plasma treatment was carried out on c-Si surface before SD. The suppression of silicon epitaxial growth was observed. This is due to the transformation of c-Si surface bonding configurations which was confirmed by measurement of Attenuated total reflectance Fourier transform infrared spectroscopy. The QSSPC and PL results indicated improved passivation quality using NF3 plasma treatment before SD. The other part of this study concerned the etching of a-Si:H (n+) layer in i/n+ a-Si:H stack using hydrogen plasma followed by in-situ re-deposition of a-Si:H(p+) layer. With the aid of in-situ deposition, the vacuum break of PECVD, HF dip of c-Si wafer prior to a-Si:H(p+) deposition, wafer rising and drying can be skipped. A sufficient c-Si surface passivation is here required after the etching and re-deposition processes. According to the SE results, a stable and uniform etching of a-Si:H(n+) film with etching rate of 1.4±0.1 nm/min was achieved. An excellent surface passivation quality with τeff of above 8ms was obtained after etching of a-Si:H(n+) and re-deposition of a-Si:H(p+) layer. A thicker a-Si:H(i) layer was proven to be beneficial to prevent passivation degradation during hydrogen plasma etching. The preliminary results suggest that this is a promising method to replace currently used etching methods that remove the whole a-Si:H(i/n+) stack, significantly simplifying rear side patterning steps for SHJ -IBC solar cell devices.
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Kumar, Praveen [Verfasser], and Oliver [Akademischer Betreuer] Eibl. "Structure-property Correlation of Front Side Metallization Contacts for High-efficiency, Single-crystalline Si Solar Cells / Praveen Kumar ; Betreuer: Oliver Eibl." Tübingen : Universitätsbibliothek Tübingen, 2018. http://d-nb.info/1198972505/34.
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Alemán, Martínez Mónica [Verfasser], and Eicke [Akademischer Betreuer] Weber. "Low temperature processes for the front-side metallization of crystalline silicon solar cells = Niedrig-Temperatur Prozesse für die Vorderseite Metallisierung von kristallinen Silizium-Solarzellen." Freiburg : Universität, 2013. http://d-nb.info/1123477647/34.
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Dufton, Jesse T. R. "Computational studies of sulphide-based semiconductor materials for inorganic thin-film photovoltaics." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607142.
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New thin-film solar cell materials and a greater understanding of their properties are needed to meet the urgent demand for sustainable, lower-cost and scalable photovoltaics. Computational techniques have been used to investigate Cu2ZnSnS4, CuSbS2 and CuBiS2 , which are potential absorber layer materials in thin-film photovoltaics. Their low cost, low toxicity and their constituent’s relative abundance make them suitable replacements for current thin-film absorbers, which are CdTe or Cu(In, Ga)(S, Se)2 based systems. Firstly, we have used hybrid Density Functional Theory (DFT) calculations to study CuSbS2 and CuBiS2. We calculate band gaps of 1.69 eV and 1.55 eV respectively, placing CuBiS2 within the optimal range for a viable absorber material. The density of states for both these materials indicate that formation of electron hole charge carriers will occur in the Cu d10 band. Consequently, photoexcitation leads to the oxidation of Cu(I). Secondly, we have derived interatomic potentials which describe the complex structure of Cu2ZnSnS4 accurately. We find that the Cu/Zn antisite defect represents the lowest energy form of intrinsic defect disorder. For these antisite defects, we find a preference for small neutral defect clusters, which suggests a degree of self-passivation exists. Investigations of Cu-ion transport find VCu migration is possible via a vacancy hopping mechanism. There are pathways which can be connected to give 3D long-range diffusion. Investigations of the Cu/Zn site disorder in Cu2ZnSnS4 find that configurations which are kesterite-like will dominate synthetic samples. However, perfectly ordered kesterite will not be formed due to entropic effects. The simulations indicate the stannite and stannite-like polymorphs are less favourable, and can only account for ≈2.5% of a sample. Investigations of the surfaces of Cu2ZnSnS4, suggest that the vast majority of the low index surfaces are dipolar and that only the (1 1 2), (0 1 0) and (1 0 1) surfaces have low surface energies.
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Jacobsson, T. Jesper. "Highly Efficient CIGS Based Devices for Solar Hydrogen Production and Size Dependent Properties of ZnO Quantum Dots." Doctoral thesis, Uppsala universitet, Oorganisk kemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-221260.
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Materials and device concepts for renewable solar hydrogen production, and size dependent properties of ZnO quantum dots are the two main themes of this thesis. ZnO particles with diameters less than 10 nm, which are small enough for electronic quantum confinement, were synthesized by hydrolysis in alkaline zinc acetate solutions. Properties investigated include: the band gap - particle size relation, phonon quantum confinement, visible and UV-fluorescence as well as photocatalytic performance. In order to determine the absolute energetic position of the band edges and the position of trap levels involved in the visible fluorescence, methods based on combining linear sweep voltammetry and optical measurements were developed. The large band gap of ZnO prevents absorption of visible light, and in order to construct devices capable of utilizing a larger part of the solar spectrum, other materials were also investigated, like hematite , Fe2O3, and CIGS, CuIn1-xGaxSe2. The optical properties of hematite were investigated as a function of film thickness on films deposited by ALD. For films thinner than 20 nm, a blue shift was observed for both the absorption maximum, the indirect band gap as well as for the direct transitions. The probability for the indirect transition decreased substantially for thinner films due to a suppressed photon/phonon coupling. These effects decrease the visible absorption for films thin enough for effective charge transport in photocatalytic applications. CIGS was demonstrated to be a highly interesting material for solar hydrogen production. CIGS based photocathodes demonstrated high photocurrents for the hydrogen evolution half reaction. The electrode stability was problematic, but was solved by introducing a modular approach based on spatial separation of the basic functionalities in the device. To construct devices capable of driving the full reaction, the possibility to use cells interconnected in series as an alternative to tandem devices were investigated. A stable, monolithic device based on three CIGS cells interconnected in series, reaching beyond 10 % STH-efficiency, was finally demonstrated. With experimental support from the CIGS-devices, the entire process of solar hydrogen production was reviewed with respect to the underlying physical processes, with special focus on the similarities and differences between various device concepts.
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Katkhouda, Kamal [Verfasser], Peter [Akademischer Betreuer] Schaaf, Edda [Akademischer Betreuer] Rädlein, and Andreas [Akademischer Betreuer] Grohe. "Aluminum-based PVD rear-side metallization for front-junction nPERT silicon solar cells / Kamal Katkhouda. Technische Universität Ilmenau. Gutachter: Edda Rädlein ; Andreas Grohe. Betreuer: Peter Schaaf." Ilmenau : Universitätsbibliothek Ilmenau, 2014. http://d-nb.info/1070505129/34.
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Yüce, Ceren [Verfasser], and N. [Akademischer Betreuer] Willenbacher. "Development of Highly Concentrated Conductive Silver Pastes for Front-Side Metallization of Silicon Solar Cells - Their Flow Properties and Printing Behavior / Ceren Yüce ; Betreuer: N. Willenbacher." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/119312669X/34.
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Preissler, Natalie [Verfasser], Daniel [Akademischer Betreuer] Amkreutz, Onno [Akademischer Betreuer] Gabriel, Bernd [Gutachter] Rech, Rutger [Gutachter] Schlatmann, and Jan [Gutachter] Schmidt. "Front-side interface engineering for liquid-phase crystallized silicon solar cells on glass / Natalie Preissler ; Gutachter: Bernd Rech, Rutger Schlatmann, Jan Schmidt ; Daniel Amkreutz, Onno Gabriel." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/115635434X/34.
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Bounaas, Lotfi. "Etude et intégration de matériaux avancés pour la passivation face arrière de cellules photovoltaïques minces." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4324.
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L'objectif d'amélioration des performances de cellules solaires sur des substrats de silicium cristallin de plus en plus en minces (< 200 µm) est indispensable à la réduction des coûts du module et donc à l'essor du photovoltaïque à l'échelle mondiale. Cette thèse se propose de répondre à la problématique d'amincissement des plaquettes sur substrats monocristallins (Cz) de type p de grande surface (239 cm2 - 180 µm) par le développement d'une structure en face arrière capable de générer un rendement de conversion élevé tout en limitant le degré de complexité du procédé de fabrication de la cellule. La solution explorée est celle des cellules à face arrière passivée et contacts localisés et les schémas de passivation étudiés s'appuient sur l'utilisation d'empilements diélectriques à base d'oxydes de silicium (SiO2) et d'aluminium (Al2O3) couplés au nitrure de silicium (SiNx). Ces travaux ont pour objectif d'optimiser les propriétés de passivation des couches diélectriques tout autant que les briques technologiques nécessaires à leur intégration dans la structure de cellule finale (conditionnement de surface, ablation laser sélective, métallisation par sérigraphie). Le procédé de fabrication résultant a permis d'obtenir des cellules avec un rendement de conversion de 19.1% pour l'empilement SiO2/SiNx. Il est cependant démontré que les limitations des performances de cette structure peuvent être partiellement compensées en introduisant une couche d'alumine, permettant d'atteindre un rendement remarquable de 19.5% (+0.4% par rapport à une structure standard)Improving the solar cell efficiency on thin wafers (< 200 µm) has become a must in the industry in order to reduce the module cost and enhance the photovoltaics field growth worldwide. This work addresses the issues regarding the thickness reduction of large monocrystalline p-type wafers (239 cm2 - 180 µm) by developing a back side architecture capable of increasing the efficiency while limiting the cell fabrication level of complexity. Thus back passivated and local contacts, also known as PERC-type, solar cells are investigated. Those include passivation schemes relying on the use of dielectric stacks based on silicon oxide (SiO2), aluminum oxide (Al2O3) both coupled with silicon nitride layers (SiNx). This PhD study attempts to carry out an optimization of the passivation properties as well as of the technological steps required for a proper integration in the final cell structure (surface preparation, selective laser ablation, screen-printing metallization). The resulting optimized process led to the fabrication of solar cells displaying an 19.1% conversion efficiency by using SiO2/SiNx layers. Nevertheless it was shown evidence that the limited electrical performances can be overcome by introducing an Al2O3 layer, eventually reaching a remarkable 19.5% efficiency. This represents an absolute gain efficiency of +0.4% compared to the standard full-area Al-BSF solar cell architecture
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Winkler, Luděk. "Charakterizace zadních stran solárních článků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218583.
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This thesis deals with the characterization back side of solar cells. In order to describe the quality of material from the point of view of a back side solar cell, the method of photoluminescence, the method of light emitting from micro plasma and LBIC (Light Beam Induced Current) is used. Gained results are compared with the results of front side analysis. Next, the thesis describes back side potential.
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Hladík, Jiří. "Analýza a optimalizace selektivních technologických procesů pro kontakty krystalických křemíkových solárních článků." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-233590.
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The submitted work deals with the methods for manufacturing and analysis of contacts on crystalline silicon solar cells. It is focused on selective processes for the production of solar cells metal contacts. The masking feature of silicon nitride is used for selective silicon etching, selective phosphorus diffusion and selective electro-less nickel deposition. Properties of metal contacts precursors are investigated using optical microscopy and their electrical properties using methods based on a four-point probe method. Results are used for the manufacturing of silicon, solar cell with an innovative type of the structure of the front side metallization: chemical nickel, conductive adhesive and copper wire. This approach allows to reduce shading of the front area of PV cells with the ability to avoid usage of busbars. The another advantage of this approach is in replacement of costly silver in at least 2/3 cross section of the front side metallization. Selective ablation of silicon nitride layer was conducted by means of IR laser beam.
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HUANG, CHENG-JING, and 黃成靖. "Research on Si-based Solar Cells with SiGe Hetero-junction." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/4mbdaa.
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Hu, Cheng-Siang, and 胡程翔. "Research on SiGe heterojunction solar cells with micro-sphere texturing (MST)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/72h5ud.
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碩士國立雲林科技大學
電子工程系
103
This research work contains three parts. The first part was to develop single micro sphere anti-reflection coating (ARC) for the crystalline silicon solar cells. Experimentally, the single ARCs with different SiO2 particle diameters (1-μm, 2-μm, 4-μm, and 8-μm) were used to make the micro sphere texturing (MST) structure on single-crystalline silicon (sc-Si) substrates with different spin coating speeds, spin times, and post-annealing temperatures. The optimum parameters for the single ARC were MST with 1-μm SiO2 particles at second spin speed of 1000 rpm for 20 seconds. The average and minimum surface reflectivity of the sc-Si substrate can be reduced to 5.8% and 4.2%, respectively, in the wavelength range of 400 – 700 nm. The second part of this research was to develop double micro sphere ARC which can improve the distribution and adhesion of the SiO2 particles on the sc-Si substrate surface. The double ARC structures were SOG combined with different SiO2 particle diameters (SOG+1-μm SiO2 and 100nm+1-μm SiO2). With double ARC, The average and minimum surface reflectivity of the sc-Si substrate can be reduced to 2.1% and 1.7%, respectively, in the wavelength range of 400 – 700 nm. The third part of this research was to integrate the MST ARC structures with sc-Si solar cells. With the MST ARCs, the photovoltaic conversion efficiencies of the solar cells were measured at different incident angles (0 degree, 20 degree, 40 degree, 60 degree, and 80 degree). The highest efficiency of the sc-Si solar cell was 8.02% obtained with double MST ARC that is 49.02% higher than the basic sc-Si solar cell without ARC. Besides, the sc-Si solar cell with double MST ARC can keep 76.2% efficiency level at an incident angle of 80 degree.
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Kuan-HaoChen and 陳冠豪. "Laser-assisted n+ Microcrystalline Silicon Tunnel Junction for a-Si/a-SiGe Tandem Solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/70479883711157994735.
Full textAbstract:
碩士國立成功大學
微電子工程研究所碩博士班
100
The topic of this research is n+ microcrystalline silicon film deposited at low temperature based on Laser-assisted Plasma-Enhanced Chemical Vapor Deposition system (LAPECVD). Since silane shows extremely high absorption coefficient to CO2 laser at certain wavelength (10.6 um), the CO2 laser beam is applied to the chamber during deposition of silicon film. It makes amorphous silicon be converted into a microcrystalline phase. In application, this research applies the high quality n+ microcrystalline silicon film to the tunnel recombination junction of the tandem solar cell consisting of an amorphous silicon top cell and an amorphous silicon-germanium bottom cell, which expects to improve a whole cell performance by better transmission capability of both top and bottom cell due to the high carrier concentration, high carrier mobility, low resistivity and low optical gap in microcrystalline film. The tunnel junction produced by Laser-assisted Plasma-Enhanced Chemical Vapor Deposition system (LAPECVD) significantly enhances efficiency of tandem solar cell from 6.40% to 8.07%, and increases the fill factor from 0.54 to 0.59.
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Ming-HsienChuang and 莊明憲. "Deposition a-Si/a-SiGe Tandem Solar Cells With Hydrogen Plasma Treatment On Flexible Substrate." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67175276752854620784.
Full textAbstract:
碩士國立成功大學
光電科學與工程學系
102
Amorphous silicon-based Solar cells are generally deposited by plasma enhanced chemical vapor deposition (PECVD) with substrate temperature 250 ℃ during the process. In this study, n-i-p structure was used to fabricate silicon-based solar cells on Polyimide (PI). However, this structure may cause poor quality and numerous surface states in the a-Si films. The H2 plasma passivation is a promising technique to improve the amorphous silicon (a-Si) solar cells. The method enhanced the efficiency of a-Si solar cells from 1.25 % to 4.22 % on glass substrate. In addition, the efficiency of flexible a-Si solar cell deposited on PI was 3.27 %. In order to further enhance the efficiency, the a-SiGe cell with absorption of infrared was combined with a-Si cell as double junction tandem solar cells. The efficiency of a-Si/a-SiGe tandem solar cells with H2 plasma passivation is 6.03 % and 4.26 % on the glass and PI substrate, respectively. Furthermore, the durability of tandem solar cells on PI was analyzed by different degree of bending and bending times. Key words：H2 plasma passivation, amorphous silicon, flexible, tandem solar cells.
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PANDEY, RAHUL. "DESIGN AND SIMULATIONS OF SiC BASED REAR CONTACT Si AND SiGe SOLAR CELLS FOR STANDALONE AND TANDEM APPLICATIONS." Thesis, 2017. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16135.
Full textAbstract:
The most abundant renewable source of energy on the earth is solar energy, yet its potential has not been exploited efficiently by solar cells present in the market. Affordability of solar energy can be enhanced, either by increasing the efficiency of a solar cell or by reducing its cost. In this thesis, several approaches for improving solar efficiency with careful design have been proposed using Technology Computer Aided Design (TCAD). These approaches attempt to improve the solar cell current, solar cell voltage, light absorption, surface recombination, and ultraviolet (UV) stability. Finally, the mechanically stacked tandem architecture addresses thermalization and lack of absorption losses for improved efficiency. The initial focus is to minimize the issues associated with thin devices such as low absorption and high surface recombination. These issues have been resolved using novel front surface design which consists of Zirconia (ZrO2) based texturing along with Silicon Carbide (SiC) based front surface passivation. Design principle balances out photonic and electronic effects together and resulted in 15.7% efficient rear contact silicon (Si) solar cell, in the sub10 µm-thick regime. The next focus is to minimize the thermalisation losses. 300 microns and 10 microns thick SiC passivated rear-contact solar cell has been placed in four terminal (mechanically stacked) tandem configuration with 20.9% efficient perovskite top subcell. Realistic TCAD analysis has been done for both top and bottom subcell; which resulted in 27.6% and 22.4% efficient tandem devices under single air mass 1.5 (AM 1.5) irradiance. Further, SiC passivated interdigitated back contact silicon heterojunction solar cell (IBCSiHJ) has also been discussed for bottom subcell application under perovskite top subcell since IBC-SiHJ solar cell uses low-temperature fabrication processes and has excellent photovoltaic (PV) performance. The efforts resulted in 29.5% and 23.7% efficient tandem devices which contain 250 µm and 25 µm thick IBC-SiHJ bottom subcells, respectively.
Si as an active material for most of the PV devices, whose absorption coefficient is small at higher wavelengths; therefore, thick silicon wafers are required to obtain greater efficiencies in both standalone as well as tandem configuration. Thicker silicon wafer eventually increases the module cost, and hence, modification in the bandgap (Eg< 1.1 eV) of the Si is required to increase the absorption of sunlight at higher wavelengths while keeping the thickness low. Therefore, Silicon-Germanium (SiGe) material has been introduced to rear contact solar cell designs and investigation is done for both standalone and tandem configuration. The thickness of SiGe based devices reported in this thesis is 10 microns, which is projected to enhance the efficiencies keeping the thickness low. The device exhibits improved higher wavelength absorption without the need of complex texturing schemes and suggested its potential use as a bottom subcell under tandem configuration. 15.4% power conversion efficiency (PCE) is reflected in convention rear contact SiGe solar cell, whereas in interdigitated back contact SiGe heterojunction solar cell (IBC-SiGeHJ) architecture, 15.5% PCE is achieved in a stand-alone configuration, and in combination with perovskite top subcell, further 25.7% PCE is demonstrated.
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Lin, Ting-Chun, and 林廷駿. "High efficiency double – junction (a-Si/a-SiGe) thin film solar cells prepared by high frequency plasma enhanced chemical vapor deposition." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/38275583310500798553.
Full textAbstract:
碩士明道大學
材料科學與工程學系碩士班
100
Abstract In this study, a-Si/a-SiGe tandem solar cells have been fabricated by 27.1 MHz very high frequency plasma enhanced chemical vapor deposition. The process parameters are optimized for a-SiGe thin film solar cells. The thickness and gas flow ratio of intrinsic a-SiGe films are varied to investigate the relevant effects. The significant increase in long-wavelength (750-900 nm) light utilization and device short-circuit current density can be achieved via adjusting the Ge content in the films. The optimal parameters of the single junction device are applied to double-junction solar cell fabrication to further improve the conversion efficiency. This study changes Ge doping ratio from 0.5% to 1.5%, hydrogen dilution ratio from 80% to 96% and intrinsic layer thickness from 100 to 250 nm to investigate the optical, electrical and structural properties of the a-SiGe films. By obtaining the optimal parameters, we expect to achieve the best a-SiGe thin film solar cells. Optical, electrical and structural properties of the films are characterized by UV-VIS-NIR spectroscopy and field emission scanning electron microscopy. I-V curves and external quantum efficiency of the devices are measured under AM1.5G (100 mW/cm2) light illumination condition.
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Tseng, Kao-Wu, and 曾高吾. "Characteristics of SiGe/Si Heterojunction Solar Cell." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/35022300992060575424.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
95
In recent years, SiGe/Si heterostructure has attracted great attention for its applications in electronic devices and optoelectronic devices. In this thesis, we use the molecular beam epitaxy technology to deposit SiGe alloy on silicon substrate to substitute for the conventional silicon material and to improve the conversion efficiency of solar cells. The influence of the doping concentration and thickness of single-crystal on device characteristics are discussed. Finally, we use simulator of solar energy AM1.5G under the illuminated condition. The four important parameters are conversion efficiency, short-circuit current, open-circuit voltage and fill factor. We measure these parameters to analyze and evaluate the performance of solar cells. Four important factors will determine the overall performance of solar cell.
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Liao, Tien-Yu, and 廖天佑. "A Simulation Study for a-SiGe Solar Cell Using AMPS-1D." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6fvgry.
Full textAbstract:
碩士國立中興大學
電機工程學系所
102
To effectively model the characteristics of solar batteries and its material properties, non-commercial simulation software known as AMPS-1D (developed by the University of Pennsylvania) was employed to construct models of amorphous silicon and hydrogenated amorphous silicon-germanium solar cells. The model of hydrogenated amorphous Si-Ge solar cells, which have an intrinsic layer (I-layer) made fromhydrogenated amorphous Si-Ge, are built by varying the material property parameters, light absorption coefficient, and the structure of basic amorphous silicon solar cells. Experimental results on actual samples prepared by Green Energy and Environment Research Laboratories (GEL) in Industrial Technology Research Institute (ITRI) were used to verify that the proposed model produces the same output characteristics. During the simulation process, the energy gap of hydrogenated amorphous Si-Ge solar cells varied with changes in its inherent properties caused by doping conditions. This further affected its light absorption performance. To simplify this model, an approximate model of light absorption coefficient was adopted and approximation procedures were established in this study. The reliability of the approximation procedures was validated using samples at ITRI. In the future, reflectance (R) and transmittance (T) coefficients will be obtained from experiments and used to derive the optimal absorption coefficient following the same approximation procedures. The characteristics of hydrogenated amorphous Si-Ge intrinsic layer and the characteristic changes of solar cells resulting from a p-n heterojunction are discussed based on the simulation results. The effect of various parameters on output characteristics was observed through varying the doping concentration and film thicknesses of p, I, and n layers. Chapter 1 indicates this study’s research motivation and presents the sunlight spectrum and fundamental characteristics of light. The relationships between transmittance and reflectance coefficients and the absorption coefficient are derived. Chapter 2 introduces components in the solar batteries, including component structure, operating mechanism, property derivation, characteristics of electric current and voltage, simplified equivalent circuit model, and various parameters. Chapter 3 utilizes AMPS-1D to model the actual samples provided by GEL at ITRI. The underlying principle and physical models of the software are introduced first, and then followed by model construction. Chapter 4 presents experimental results and discussion. The output characteristics of single layer amorphous Si and nanocrystalline Si solar cells with different film thicknesses and doping concentrations were observed. To achieve the optimal energy gap structure of multi-junction amorphous solar cells, the conversion efficiency of multi-junction amorphous Si and nanocrystalline Si solar cells was studied by varying film thickness and energy gap of Tunnel Recombination Junction (TRJ) and changing the energy gap of multi-junction amorphous Si and nanocrystalline Si absorption layer. Finally, the conclusions are drawn in Chapter 5.
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Lin, Che-Yung, and 林哲永. "Isolation Technique for SiGe Power Amplifiersand Simulation of Solar Cell Characteristics." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/04113072391534573986.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
96
In this thesis, an isolation technique for dual power amplifiers is introduced. For the isolation of dual power amplifiers, the equivalent coupling effect at 2.45GHz before laser cut is -24.7dB, after first laser cut is -27.2dB and after second laser cut is -29.25dB. The EVM at 3% criterion after first laser cut of standalone condition is 11.4dBm, of equal power is 8.9dBm and of 10dB larger input power from down-PA is 7.8dBm. After second laser cut the EVM at 3% criterion of standalone condition is 15dBm, of equal power is 13.9dBm and of 10dB larger input power from down-PA is 9.8dBm. The small signal gain, P1dB and PAE at P1dB are 18.6dB, 25.3dBm and 16.7%, respectively. By measuring electrical characteristics of commercial solar cells, the solar cell model can be established in ISE. Furthermore, the optimization simulations of doping profile, finger width and spacing and nano texture are performed.
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Hsu, San-Shon, and 許勝雄. "Simulation study of a-Si/a-SiGe multi-junction solar cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/46478746951442554221.
Full textAbstract:
碩士國立中興大學
電機工程學系所
98
To improve power conversion efficiency is always a focal point for research and development of solar cell, and one of the methods is making use of multi-junction solar cell. Hence, to find out the characteristics of multi-junction solar cell is the objective of the study. In this study, TCAD software (ATLAS) is used to simulate and build the model of thin-film solar cell, and furthermore ITRI trial run data is referred as the basis information of single-junction solar cell and multi-junction solar cell. For the single-junction solar cell part, a-Si and a-SiGe are taken as main materials for absorption layer, then respectively change every layer’s concentration, thickness and absorption layer’s defect of p、i、n, so as to discuss the influence of these factors for a-Si and a-SiGe.。 For the multi-junction solar cell part, single-junction a-Si and a-SiGe thin-film solar cell are used as the foundation to form the structure of a-Si/a-SiGe multi-junction solar cell. Two different energy gap materials are also used to be the major absorption layer for top and bottom solar cell. Using multi-junction solar cell is able to increase open voltage, and it’s an efficient way of utilizing solar spectrum to avoid the waste of power. It can improve power conversion efficiency of solar cell.
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Lin, Che-Yung. "Isolation Technique for SiGe Power Amplifiers and Simulation of Solar Cell Characteristics." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2107200820120000.
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Chang, Chi-Yuan, and 張集淵. "High performance organic solar cells with dual side photon harvest capability." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/88058893920865603374.
Full textAbstract:
碩士國立臺灣大學
應用物理所
102
This thesis mainly focuses on the research of inorganic/organic hybrid solar cells. The inorganic/organic hybrid solar cells are made from ZnO nanoparticles, V2O5, and P3HT/PCBM. After cleaning the ITO glass, ZnO nanoparticles were spin coated on the silver nanowires followed by spin-coating P3HT/PCBM as the active layer. After that, V2O5 was deposited on the active layer through spin-coating method as well. We then transferred the CVD graphene onto the V2O5 layer as the top electrode to make the solar cell that can absorb luminous energy from double sides. Further, we doped the gold nanoparticles into the V2O5 layer to improve the performance of the photovoltaic devices by taking advantage of the surface plasmon resonance effect of the metallic nanospheres.. This device features for all solution process, low cost, and diverse applications. According to our study, the main reasons for the increased efficiency of solar cells can be attributed to the surface plasmon resonance effect from the Au nanoparticles, exporting more charges out of the active layer. An improved device performance is thus achieved.
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Tsai, Ming-Chun, and 蔡茗竣. "Fabrication and Study of InterdigitatedBack-side Metal Contact Silicon Nanowires Based Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/55997592079632605110.
Full textAbstract:
碩士國立雲林科技大學
機械工程系碩士班
99
The objective of this study is to fabricate and study the interdigitated back-side metal contact (IBC) silicon nanowires (SiNWs) based solar cells. In this thesis, the feasibility study was done which included with the (1) designs of structures, fabrication processes and photomask layouts of IBC SiNWs based solar cells, (2) texturing and saw damage removal of silicon wafer by using the different KOH solution, (3) PECVD Si3N4 antireflective coating (ARC), (4) phosphorous and boron ions thermal diffusion for the formations of p+ and n+ emitters, and (5) SiNWs formation by using electroless metal deposition (EMD). The testing results show that the micropyramids texture with a structure size range of 5-7μm were formed by using the 1.8 % KOH solution at 80oC for 18 min. The KOH concentrations in the range of 35-45% at 80oC were used to remove the contaminants and saw damages on the surface of silicon wafer completely after a chemical mechanical pulishing (CMP) process. The antireflective coating result shows that a bi-layer of SiOx (thermal dry oxide)/Si3N4 (PECVD) with a thickness of 800A obtained a lowest reflectance of near 0% in the wavelength range from 500nm to 700nm and an average reflectance of less than 5% in the wavelength range from 400nm to 1100nm. The sheet resistances (Rs) of p+ and n+ emitters were a range of 0.5-2.0 Kohm/square and a range of 10-30 ohm/square by using the phosphorous and boron ion thermal diffusion processes, respectively. The SiNWs array shapes of (100) Si and (110) Si was vertical and inclined after the AgNO3/HF mixed acids etching, respectively. The SiNWs array of (100) Si obtained an average reflectance of less than 5% without using ARC film in the wavelength range from 300nm to 1100nm.
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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.
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Kuan-FuLu and 呂冠輹. "The graded SiGe absorption layer solar cell deposited by Laser-Assisted Plasma EnhancedChemical Vapor Deposition." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/41786554359279583524.
Full textAbstract:
碩士國立成功大學
微電子工程研究所碩博士班
100
In general, a solar cell structure consists of an absorber layer, in which the photons of an incident radiation are efficiently absorbed resulting in a creation of electron-hole pairs. The photo-generated electrons and holes are driven by the built-in electric field of the junction to form the photo-current. The transmission capacity of electron was much better than the hole. Therefore, before the holes were driven to the contacts, the holes were recombined at defects. As this result, the photo-current is diminished. On other words, to obtain high performance, the transmission capacity of hole should be improved. On the other hand, the transmission capacity is determined by the built-in electric field, in which it should be as high as possible . In this study, the a-SiGe thin film was applied to the absorber layer of solar cells. The energy band-gap of amorphous silicon–germanium (a-SiGe) alloy can be adjusted continuously between 1.4 eV and 1.8 eV by varying the Ge fraction. This characteristic renders a-SiGe a suitable light absorber material in multi-junction amorphous silicon (a-Si) based thin film solar cells, in which the a-SiGe acts as intrinsic layer in middle or bottom cells to enhance green to red absorption . The high performance silicon-germanium (a-SiGe) solar cells with graded absorber layer and microcrystalline structure doped thin films (p-Si and n-Si) was fabricated by using laser-assisted plasma-enhanced chemical vapor deposition (LAPECVD) system. These experimental results verified that the solar cells with graded absorber layer was improved from 19.43 mA/cm2 to 23.54 mA/cm2. Consequently, the conversion of the solar cells efficiency was upgraded from 5.46 % to 6.83 %. Furthermore, the short circuit current density of the solar cells with graded absorber and microcrystalline structure doped thin films (p-Si and n-Si) layer was improved from 19.43 mA/cm2 to 26.3 mA/cm2. Consequently, the conversion of the solar cells efficiency was upgraded from 5.46 % to 7.51 %.
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Cai, Jheng-Yan, and 蔡政諺. "Simulation for Cu-platted Front Side Metallization of Si-based Solar Cell." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/v7evnw.
Full textAbstract:
碩士國立中央大學
物理學系
105
In recent decades, the solar energy techniques grow very quickly. Because solar energy cannot exhaust greenhouse gas that is the main cause of greenhouse effect. Currently, the solar cell cannot be commonly employed since its price is still expensive. Our goal in this study is to greatly reduce the cost but only losing little efficiency. One solution is to replace a portion of silver front side metallization by copper. In our simulation, we change number, height and composition of fingers to simulate solar cell efficiency. First, we obtained the parameters which are independent of fingers, and then used PC1D to calculate cell’s IV-data. Secondly, the single diode model is employed to obtain the short circuit current, the series resistance which are independent fingers, dark current, the ideal factor and the shunt resistances. Finally, once the finger’s electrical and structural parameters are included, the cell’s efficiency can be calculated. For cupper-plated front side metallization, the simulation process is similar but considering electric and structural parameters of copper. We discussed the relations between silver height, copper height and efficiency; and the relation between widening ratio and efficiency. By comparing single layer finger with Cu-plated finger, we successfully reduce about 24.47% of Ag with additional 21.38% of Cu , while, only 0.012% of efficiency is losing. This reveals a promising reduction of cost in Si-based solar cell with Cu-platted front side metallization. Finally, we propose a promising calculation tools, combining the PC1D and circuit model, to simulate the best combination of Si-based solar cell with Cu-platted front side metallization, as long as the real electrical and structural parameters implemented from experimental results.
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Mette, Ansgar [Verfasser]. "New concepts for front side metallization of industrial silicon solar cells / vorgelegt von Ansgar Mette." 2007. http://d-nb.info/986867144/34.
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Han, Liang-Yu, and 韓喨宇. "Study of Single Crystalline Silicon Solar Cells with Deeply Etched Trenches on the Rear Side." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38870849302628652191.
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Huang, Li-Yen, and 黃立妍. "Study of Selective Emitter Solar Cells with Rear-Side Trenches Deeply Etched by Wet Etching." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/87220499018655921458.
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Liu, Chun-Wei, and 劉俊偉. "Preparation and Electro-optical Properties of Rear Side Silver Electrode on Crystalline-silicon Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/g28569.
Full textAbstract:
碩士國立高雄應用科技大學
化學工程與材料工程系碩士在職專班
106
In this study, the conductive silver pastes were prepared by blending various morphology, tape density and sizes of spherical silver powders with bismuth oxide and milled glass frit in different content as the rear side silver electrode of crystalline silicon solar cell. Photovoltaic properties and tension characteristics of back electrode pastes are investigated by IV-tester, force apparatus and scanning electron microscope after screen printing and co-firing by furnace. We are looking forward to develop a high performance of crystalline silicon solar cell rear electrode silver paste. Results showed that the rear electrode silver paste containing D90 particle size of 1.0µ and tap density of 4.2g/cm3 spherical silver powder with 1.5 wt% bismuth oxide and milled glass frit exhibits highly dense and uniform surface morphology of back electrode after firing by peak temperature of 770℃, the highest efficiency of 17.828% and welding tension of 5.494N of the rear side silver electrode of crystalline silicon solar cell can be obtained.
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Chen, Wei, and 陳瑋. "Fabrication and Characteristics of Solar Cell Back Side Passivation by Ultrasonic Spray Pyrolysis." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/41707565775394263432.
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Lee, Wan-Hua, and 李婉華. "Synthesis of 5,6-Difluorobenzo[1,2,5]thiadiazole Derivative Based Side-Chain Conjugated Polymers for Photovoltaic Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/40647060280272267827.
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碩士國立中興大學
化學工程學系所
103
In this study, 5,6-difluorobenzo[1,2,5]thiadiazole derivative (BT-F) based conjugated polymers with different content of triphenylamine based pendants were synthesized via stilling coupling reactions. The absorption pecks of PBTFA11 were observed at 417.1, 557.2, and 717.0 nm. The absorption pecks of PBTFA12 were observed at 417.3 and 576.2 nm . In addition, two absorption pecks of PBTFA13 were observed at 416.2 and 556.6 nm. The UV-vis absorptin wavelength was red-shiffed as BT-F cintent was increased. The bandgap energies of PBTFA11,PBTFA12, and PBTFA13 were 1.54,1.59,and 1.69 eV, respectively. A series of bulk heterojuction solar cells based on the active layer of PBTFA11/PC61BM, PBTFA12/PC61BM, and PBTFA13/PC61BM blends were fabricated. The morphologise of polymer/PC61BM blend films were studied by AFM. AFM images indicated that the polymer and PC61BM were phase separated in nanoscale. This is favorable for the charge separation and transefer of the carriers.The power conversion efficiency (PCE) was strongly dependent on the composition of the blends. The PCE values of PBTFA13/PC61BM based solar cells were larger than those of PBTFA11/PC61BM and PBTFA12/PC61BM based solr cells. A power conversion efficiency (PCE) of 0.92%, a short-circuit current density of 3.30mA/cm2 , an open-circuit voltage of 0.59 V , and a fill factor of 0.47 were observed for solar cell based on the active layer PBTFA13/PC61BM (1:3, w/w). The PCE value of PBTFA13 based PSC was further enhanced to 3.02% by using the PBTFA13/PC71BM blend film as photoactive layer.
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Yang, Lun-Cheng, and 楊淪証. "Synthesis of Diethylene Glycol Functionalized Diketopyrrolopyrrole Derivatives Based Side-Chain Conjugated Polymers For Photovoltaic Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/41637032846014352636.
Full textAbstract:
碩士國立中興大學
化學工程學系所
103
We synthesized four two-dimensional (2-D) conjugated polymers, including diethylene glycol functionalized diketopyrrolopyrrole derivatives PEGA13, PEGA12, PEGA11, and 2-ethylhexyl functionalized diketopyrrolopyrrole derivative PEHA13 featuring thionphene as π-conjugation bridge in the polymer backbones and appending conjugated triphenylamine/thiophene (TPATh) moieties on the side chains. Excellent thermal stability was observed for PEGA13, PEGA12, PEGA11, and PEHA13. Incorporating the thiophene into the polymer backbones and appending TPATh units indused high degrees of intramolecular charge transfer within the conjugated framework of the polymers, thereby resulting in low band gap energies and red-shifting of the maximal UV-Vis absorption wavelengths. The PEGA13, PEGA12, PEGA11, and PEHA13 show two absorption bands in the range of 350-900 nm, corresponding to the band gaps of 1.42, 1.38, 1.38, 1.46 eV, respectively. The performance of the OSCs was modified significantly with varied of PEGA13 (or PEHA13)/PC61BM (or PC71BM) weigh ratio. A power conversion efficiency of 3.1 %, a short-circuit current density of 13.2 mA/cm2, an open-circuit voltage of 0.64 V, a fill factor of 0.37, and a hole mobility of 3.32×10-5 were observed for OSCs based on the active layer of PEGA13/PC71BM (1:2, w/w).
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"Development of New Front Side Metallization Method of Aluminum Electroplating for Silicon Solar Cell." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.48478.
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abstract: In this thesis, the methods of aluminum electroplating in an ionic liquid for silicon solar cell front side metallization were studied. It focused on replacing the current silver screen printing with an alternative metallization technology using a low-cost Earth-abundant metal for mass production, due to the high cost and limited availability of silver. A conventional aluminum electroplating method was employed for silicon solar cells fabrication on both p-type and n-type substrates. The highest efficiency of 17.9% was achieved in the n-type solar cell with a rear junction, which is comparable to that of the same structure cell with screen printed silver electrodes from industrial production lines. It also showed better spiking resistant performance than the common structure p-type solar cell. Further efforts were put on the development of a novel light-induced plating of aluminum technique. The aluminum was deposited directly on a silicon substrate without the assistance of a conductive seed layer, thus simplified and reduced the process cost. The plated aluminum has good adhesion to the silicon surface with the resistivity as low as 4×10–6 -cm. A new demo tool was designed and set up for the light-induced plating experiment, aiming to utilize this technique in large-size solar cells fabrication and mass production. Besides the metallization methods, a comprehensive sensitivity analysis for the efficiency dispersion in the production of crystalline-Si solar cells was presented based on numerical simulations. Temperature variation in the diffusion furnace was the most significant cause of the efficiency dispersion. It was concluded that a narrow efficiency range of ±0.5% absolute is achievable if the emitter diffusion temperature is confined to a 13˚C window, while other cell parameters vary within their normal windows. Possible methods to minimize temperature variation in emitter diffusion were proposed.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2018
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Hung, shih-shiu, and 洪世修. "Fluorene-based ladder-type haptacyclic arene with aliphatic side chains for polymer solar cell applications." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/64814627124696630616.
Full textAbstract:
碩士國立交通大學
應用化學系碩博士班
99
In this research, we have successfully developed a ladder-type heptacyclic fluorene-dicyclopentadithiophene (FDCT) unit in which two outer thiophene subunits are covalently fastened to the central 2,7-fluorene core. A three-step synthetic approach including Friedel-Crafts acylation, Wolff-Kishner reduction and alkylation was designed to successfully incorporate four octyl chains on the cyclopentadiene rings embedded in the conjugated backbone. By varying the ratio of corresponding monomers, the Br-FDCT-C8 building block was copolymerized with 4,7-dibromobenzothiadiazole and 2,5-trimethyltin thiophene units by Stille coupling to obtain two random donor-acceptor copolymers, r-PFDCTBT11 and r-PFDCTBT12, respectively. On the other hand, Br-FDCT-C8 also reacted with 4,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-(2,1,3-benzothiadiazole) to afford an alternating copolymer PFDCTBT-C8 by Suzuki polymerization. Bulk heterojunction devices (ITO/PEDOT:PSS/polymer:PC71BM/Ca/Al) were fabricated to evaluate these polymers. The devices based on r-PFDCTBT11 and r-PFDCTBT12 exhibited moderate power conversion efficiencies of 2.95% and 2.50%, respectively. Encouragingly, the device incorporating PFDCTBT-C8/PC71BM blend (1:3.5 in wt%) showed a Voc of 0.80 V, a Jsc of 10.86 mA cm-2, a FF of 57.6%, delivering an impressive PCE of 5.01 %. The PFDCTBT-C8 also showed a high mobility of 0.03 cm2 V-1 S-1 measured from the field-effect transistor device, which is in good agreement with its high current density. This improved performance is associated with the modification of aliphatic side chains on FDCT structure to optimize the interchain interactions for enhanced charge transporting. Considering that the solar cells with inverted configuration possess much enhanced stability, performance of PFDCTBT-C8 copolymer in the inverted device was also investigated. The device based on ITO/ZnO/C-PCBSD/PFDCTBT-C8:PC71BM (1:3, w%)/PEDOT:PSS/Ag exhibited a Voc of 0.83 V, a Jsc of 10.25 mA cm-2, a FF of 55.7%, delivering a high PCE of 4.8%. Additive processing is known to be an effective strategy to control the optimized morphology. By incorporating small amount of 1-chloronaphthalene into the active layer solution (2.5%, v/v) as the additive, the corresponding device exhibited much improved performance, showing a high PCE of 6.7% with a Voc of 0.83 V, a Jsc of 12.29 mA cm-2, a FF of 65.6%. This value represents one of the best performance among fluorine-based conjugated polymers in the literature. By taking advantage of low temperature device fabrication process, a flexible polymer solar cell was fabricated by replacing the ITO glass substrate with the flexible polyethylene naphthalate (PEN) substrate. This device exhibited a high PCE of 5.6%.
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Chu, Jia-Yi, and 朱佳儀. "Effects of Branched Side Chain on the Physical Properties and Solar Cell Performance of Polythiophene." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/kqhz6c.
Full textAbstract:
碩士國立臺灣大學
高分子科學與工程學研究所
107
Over the past decade, the polymer/fullerene-based organic solar cell has rapidly developed. In addition to the increase of power conversion efficiency (PCE) by adding additives or synthesizing new structure, the improvement of stability has also been a key issue for the organic solar cell. In this study, we synthesized poly(3-2-methylpentylthiophene) (P3MPT), a polythiophene with branched side chain and studied the morphology, thermal properties, and photovoltaic performance of P3MPT blended with different fullerene derivatives. The results are compared to those of the commonly used poly(3-hexylthiopene) (P3HT) with linear side chains to investigate the effects of side chain configuration. We found that P3MPT/PC61BM solar cells not only show a higher efficiency but can maintain the high efficiency much longer than the P3HT/PC61BM solar cells. Compared to P3HT/PC61BM systems, the size of domains extracted by the small-angle X-ray scattering (SAXS) profiles implies a more stable phase separated structure in P3MPT/PC61BM blends. We suggest that the branched side chains are bulkier than the linear side chains and thus can provide a higher steric hindrance, which causes more rigid side chains and backbones to slow down the phase separation rate between P3MPT and PC61BM. The higher glass transition temperature of P3MPT than that of P3HT was confirmed by differential scanning calorimetry (DSC). In addition, DSC and Wide-angle X-ray scattering show that the crystallization ability of P3MPT is lower than that of P3HT also due to the bulkier side chains. The higher glass transition temperature and the lower crystallization ability of P3MPT contribute to the superior long-term stability of P3MPT/PC61BM system.
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Yeh, Kaun-Liang, and 葉冠樑. "Introducing alkyl side chains with different symmetry to conjugated polymers for application in bulk heterojunction polymer solar cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/28028988104080474277.
Full textAbstract:
碩士國立交通大學
材料科學與工程學系所
104
In this study, in order to investigate the characteristics of bulk heterojunction polymer solar cell through changing polymer alkyl side chains, we use benzodithiophene (BDT) with alkyl thienyl side chains as electron donor, thiophene as π-bridge, and benzooxadiazole (BO) as electron acceptor. By changing the alkyl side chains of BDT and BO into linear or branched structure, we synthesize a series of donor-π-acceptor (D-π-A) conjugated polymers－PBDTTC8TBOC8C8 (P1), PBDTTC8TBOEHEH (P2), PBDTTC8TBOC8EH (P3), PBDTTEHTBOC8C8 (P4), PBDTTEHTBOEHEH (P5), PBDTTEHTBOC8EH (P6) respectively. We systematically compare the physical, chemical, photovoltaic, structural packing, and morphological properties. P1 has the highest thermal stability, number-average molecular weights (Mn), and weight-average molecular weights (Mw). P1, P2, P3, and P4 films tend to form face-on packing structures which is beneficial to carrier transfer orthogonally, thus show enhanced shortcut current (Jsc). P2 and P3 have low-lying HOMOs, leading to high open circuit voltage (Voc) which are 0.93 V and 0.90 V, respectively. These high Voc cause P2 and P3 to achieve power conversion efficiency (PCE) of 6.5% and 6.8%. P4 exhibit the widest FWHM owing to its broad absorption range with more obvious red shift, and its λonset is 706 nm. The Jsc and PCE of P4 are 15.7 mA/cm2 and 7.5%.