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Готові списки джерел за темами / CdTe polycrystalline thin film / Статті в журналах

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Статті в журналах з теми "CdTe polycrystalline thin film"

Автор: Grafiati

Опубліковано: 11 березня 2023

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1

Yan, Y., K. M. Jones, and M. M. Al-Jassim. "Transmission Electron Microscopy Study of Planar Defects in Polycrystalline CdTe Thin Films." Microscopy and Microanalysis 7, S2 (August 2001): 556–57. http://dx.doi.org/10.1017/s1431927600028853.

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Анотація:

CdTe is a promising photovoltaic material due to its near optimum band gap and high absorption coefficient. Polycrystalline, thin-film CdTe/CdS solar cells have demonstrated an efficiency of 15.8%. High density of extended defects is often found in polycrystalline CdTe films grown by close-spaced sublimation (CSS). So far, most investigations of defects in CdTe have focused on epitaxially grown films, and the reported extended defects are mainly lamellar twins. However, epitaxially grown films generally have a different microstructure compared to CSS grown polycrystalline CdTe thin films. in this paper, we report our study of extended defects in CSSgrown polycrystalline CdTe thin films by high-resolution transmission electron microscopy (HRTEM). We found that the extended defects are mostly lamellar twins and stacking faults. The stacking faults always propagate across the grains, without ending at a partial dislocation inside the grains.

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2

Jones, K. M., F. S. Hasoon, A. B. Swartzlander, M. M. Al-Jassim, T. L. Chu, and S. S. Chu. "The morphology and microstructure of polycrystalline CdTe thin films for solar cell applications." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1384–85. http://dx.doi.org/10.1017/s0424820100131553.

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Polycrystalline thin films of II-VI semiconductors on foreign polycrystalline (or amorphous) substrates have many applications in optoelectronic devices. In contrast to the extensive studies of the heteroepitaxial growth of compound semiconductors on single-crystal substrates, the nucleation and growth of thin films of II-VI compounds on foreign substrates have received little attention, and the properties of these films are often controlled empirically to optimize device performance. A better understanding of the nucleation, growth, and microstructure will facilitate a better control of the structural and electrical properties of polycrystalline semiconductor films, thereby improving the device characteristics. Cadmium telluride (CdTe) has long been recognized as a promising thin-film photovoltaic material. Under NREL's sponsorship, the University of South Florida has recently developed a record high efficiency (14.6% under global AM1.5 conditions) thin-film CdS/CdTe heterojunction solar cell for potential low-cost photovoltaic applications. The solar cell has the structure:glass (substrate)/SnO2:F/CdS/CdTe/HgTe (contact)The CdS films were grown from an aqueous solution, while the CdTe films were deposited by the closespaced sublimation method.

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3

Suntola, T. "CdTe Thin-Film Solar Cells." MRS Bulletin 18, no. 10 (October 1993): 45–47. http://dx.doi.org/10.1557/s088376940003829x.

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Анотація:

Cadmium telluride is currently the most promising material for high efficiency, low-cost thin-film solar cells. Cadmium telluride is a compound semiconductor with an ideal 1.45 eV bandgap for direct light-to-electricity conversion. The light absorption coefficient of CdTe is high enough to make a one-micrometer-thick layer of material absorb over 99% of the visible light. Processing homogenous polycrystalline thin films seems to be less critical for CdTe than for many other compound semiconductors. The best small-area CdTe thin-film cells manufactured show more than 15% conversion efficiency. Large-area modules with aperture efficiencies in excess of 10% have also been demonstrated. The long-term stability of CdTe solar cell structures is not known in detail or in the necessary time span. Indication of good stability has been demonstrated. One of the concerns about CdTe solar cells is the presence of cadmium which is an environmentally hazardous material.

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4

Dabban, Mehdi Ahmad, and Abdel-naser A. M. Alfaqeer. "Enhancement in microstructural and optical properties of thermally evaporated CdTe/CdSe heterojunction thin Films." University of Aden Journal of Natural and Applied Sciences 26, no. 2 (January 28, 2023): 273–84. http://dx.doi.org/10.47372/uajnas.2022.n2.a14.

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Анотація:

The optimization of microstructural and optical properties of a thin layer is an important step prior device fabrication process, so an enhancement in these properties of thermally evaporated CdTe/CdSe thin films was reported in this work. We choose to research (CdSe) materials as a n-type absorber layer in the CdTe/CdSe heterojunction thin film. The Effect of annealing temperature on the structural and optical properties of CdTe/CdSe Heterojunction thin films was studied, using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Double-beam computer-controlled spectrophotometer in the wavelength between 200 nm and 2500 nm. Diffraction (XRD) patterns showed that the as-prepared films were amorphous nature, whereas the annealed films were polycrystalline. These results were confirmed by scanning electron microscopy investigations. It was found that the crystallite size and degree of crystallinity of the studied films depend on the annealing temperature. Furthermore the optical measurement shows that this treatment shifts the optical absorption edge at low energy and decreases the optical band gap from 1.92 eV, to 1.37eV while the values Urbach energy increase as the annealing temperature increased from 300 K to 433 K. As consequence is that the heat treatment improves the quality of the CdTe/CdSe heterojunction thin films for the potential use in photovoltaic applications.

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5

K, Ramya, and Yuvaraja T. "Visual and Surface Properties of CdTe Thin Films on CdS/FTO Glass Substrates." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 2 (April 1, 2016): 468. http://dx.doi.org/10.11591/ijece.v6i2.9064.

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<p>Cadmium telluride (CdTe) thin film material was deposited ontop of Cadmium Sulfide (CdS) substrate using vacuum evaporation technique. The sample was characterized using X-ray diffraction(XRD) and UV-VIS-NIR spectroscopy. XRD studies revealed that the sample was polycrystalline in nature. The SEM image showed that the sample is columnar in structure and the grains are uniform. Optical band gap of the CdTe thin film was estimated from transmittance and reflectance data and it was found 1.53eV.The structural, optical and surface properties of the film showed that the CdTe thin film materials can be used for fabrication of CdTe thin film solar cell.</p>

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6

K, Ramya, and Yuvaraja T. "Visual and Surface Properties of CdTe Thin Films on CdS/FTO Glass Substrates." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 2 (April 1, 2016): 468. http://dx.doi.org/10.11591/ijece.v6i2.pp468-473.

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Анотація:

<p>Cadmium telluride (CdTe) thin film material was deposited ontop of Cadmium Sulfide (CdS) substrate using vacuum evaporation technique. The sample was characterized using X-ray diffraction(XRD) and UV-VIS-NIR spectroscopy. XRD studies revealed that the sample was polycrystalline in nature. The SEM image showed that the sample is columnar in structure and the grains are uniform. Optical band gap of the CdTe thin film was estimated from transmittance and reflectance data and it was found 1.53eV.The structural, optical and surface properties of the film showed that the CdTe thin film materials can be used for fabrication of CdTe thin film solar cell.</p>

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7

Asher, S. E. "Secondary Ion Mass Spectrometry Studies of Polycrystalline Thin-Film Cdte/Cds Solar Cells." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 2 (August 12, 1990): 304–5. http://dx.doi.org/10.1017/s0424820100135125.

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Анотація:

Polycrystalline thin films of CdTe deposited on CdS are one of the most promising materials systems currently being investigated for the fabrication of low cost, large area, high efficiency photovoltaic devices. However, many of the deposition processes being used to fabricate these thin film materials have not yet been well characterized. It has been found that a post-fabrication heat-treatment is necessary to improve the quantum efficiency of these devices. Secondary ion mass spectrometry (SIMS) was used to study the interdiffusion of S and Te in CdTe/CdS structures grown by two different methods. The depth profiles revealed significant differences in the sputtering behavior depending on the film morphology.Two sets of CdTe/CdS samples were studied. The first set of films was deposited at high temperature using a spray pyrolysis technique with no post deposition anneal. The second set of films was electroplated, followed by treatment with CdCl2 and a high temperature anneal.

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8

Ginting, M., and J. D. Leslie. "Preparation and electrical properties of heterojunctions of ZnO on Zn3P2 and CdTe." Canadian Journal of Physics 67, no. 4 (April 1, 1989): 448–55. http://dx.doi.org/10.1139/p89-080.

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Анотація:

"Heterojunctions" have been fabricated by the reactive evaporation of thin film n-type ZnO onto p-type single crystal Zn3P2, polycrystalline films of Zn3P2, and single crystal CdTe. The photovoltaic response of the n-ZnO – single crystal p-CdTe devices was good, that of the n-ZnO – single crystal p-Zn3P2 devices was poor, and that of the n-ZnO – p-Zn3P2 polycrystalline film devices was nonexistent. The ideality factor n of all devices studied was greater than two. On the basis of 1/C2 vs. V results, the n-ZnO – single crystal p-Zn3P2 devices behaved most like Schottky barrier devices, whereas the n-ZnO – p-Zn3P2 polycrystalline film devices, and the n-ZnO – p-single crystal CdTe "heterojunctions" behaved most like metal–insulator–semiconductor devices. The high series resistance of all devices had to be considered in the measurement and analysis, and it limited the photovoltaic performance. Deep-level transient spectroscopy measurements indicated majority (hole) traps in the CdTe and Zn3P2 with activation energies in agreement with previous measurements in the literature.

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9

Gaewdang, Thitinai, N. Wongcharoen, P. Siribuddhaiwon, and N. Promros. "Influence of Substrate Temperature on Some Properties of Close-Spacing Thermally Evaporated CdTe Thin Films." Advanced Materials Research 55-57 (August 2008): 881–84. http://dx.doi.org/10.4028/www.scientific.net/amr.55-57.881.

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CdTe thin films with different substrate temperatures have been deposited by thermal evaporation method on glass substrate in vacuum chamber having low pressure about 3.0x10-5 mbar. According to XRD analysis, CdTe thin films are polycrystalline belonging to cubic structure with preferential orientation of (111) plane. The strongest peak intensity of XRD is observed in the film prepared with substrate temperature of 150°C. Band gap and band tail values of the as-deposited films were evaluated from the optical transmission spectra. The lowest dark sheet resistance value was obtained from the film prepared with substrate temperature of 150°C as well. Regarding to our experimental results, it may be indicated that the 150°C substrate temperature is the most suitable condition in preparing CdTe thin films for solar cell applications.

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10

Hussain, K. M. A., T. Faruqe, J. Parvin, S. Ahmed, Z. H. Mahmood, and Ishtiaque M. Syed. "Preparation of CdTe Nuclear Detector Material in Thin Film Form using Thermal Evaporation Method." Malaysian Journal of Medical and Biological Research 4, no. 1 (June 30, 2017): 29–34. http://dx.doi.org/10.18034/mjmbr.v4i1.421.

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A study is initiated about cadmium telluride (CdTe) materials deposition and characterization for radiation detector application. The CdTe thin film was grown on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. Three different samples were prepared where film thickness were 500, 600 and 700 nm measured by insitu quartz crystal thickness monitoring device during deposition process. The structural studies of the films were carried out using (X-ray diffraction) XRD analytical study and optical measurements were performed in the UV-VIS-NIR region using a spectrophotometer. The films grown at room temperature are polycrystalline as found by X-ray diffraction peaks. The optical transmission spectra of CdTe films showed a high transmission of about 85% to 90% in the visible region with a sharp fall near the fundamental absorption at 880 nm wavelength for the 500 and 600 nm films, and fundamental absorption at 1270 nm wavelength for 700 nm film.

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11

Li, Xun, Dexiong Liu, and Deliang Wang. "Anharmonic phonon decay in polycrystalline CdTe thin film." Applied Physics Letters 112, no. 25 (June 18, 2018): 252105. http://dx.doi.org/10.1063/1.5033987.

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12

Wu, Xuanzhi. "High-efficiency polycrystalline CdTe thin-film solar cells." Solar Energy 77, no. 6 (December 2004): 803–14. http://dx.doi.org/10.1016/j.solener.2004.06.006.

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13

Aguirre, Rodolfo, Jose J. Chavez, Xiaowang Zhou, and David Zubia. "High Fidelity Polycrystalline CdTe/CdS Heterostructures via Molecular Dynamics." MRS Advances 2, no. 53 (2017): 3225–30. http://dx.doi.org/10.1557/adv.2017.440.

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ABSTRACTMolecular dynamics simulations of polycrystalline growth of CdTe/CdS heterostructures have been performed. First, CdS was deposited on an amorphous CdS substrate, forming a polycrystalline film. Subsequently, CdTe was deposited on top of the polycrystalline CdS film. Cross-sectional images show grain formation at early stages of the CdS growth. During CdTe deposition, the CdS structure remains almost unchanged. Concurrently, CdTe grain boundary motion was detected after the first 24.4 nanoseconds of CdTe deposition. With the elapse of time, this grain boundary pins along the CdS/CdTe interface, leaving only a small region of epitaxial growth. CdTe grains are larger than CdS grains in agreement with experimental observations in the literature. Crystal phase analysis shows that zinc blende structure dominates over the wurtzite structure inside both CdS and CdTe grains. Composition analysis shows Te and S diffusion to the CdS and CdTe films, respectively. These simulated results may stimulate new ideas for studying and improving CdTe solar cell efficiency.

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14

Tariq, G. H., and M. Anis-ur-Rehman. "Comparison of Structural Properties of Thermally Evaporated CdTe Thin Films on Different Substrates." Key Engineering Materials 510-511 (May 2012): 429–35. http://dx.doi.org/10.4028/www.scientific.net/kem.510-511.429.

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Анотація:

The direct energy band gap in the range of ~1.5eV and the high absorption coefficient (~105cm-1) makes Cadmium Telluride (CdTe) a suitable material for fabrication of thin film solar cells. Thin film solar cells based on CdTe (~ 1cm area) achieved efficiency of 15.6% on a laboratory scale. CdTe thin films were deposited by thermal evaporation technique under vacuum 2×10-5mbar on glass and stainless steel (SS) substrates. During deposition substrates temperature was kept same at 200C for all samples. The structural properties were determined by the X-ray Diffraction (XRD) patterns. All samples exhibit polycrystalline nature. Dependence of different structural parameters such as lattice parameter, micro strain, and grain size and dislocation density on thickness was studied. Also the influence of the different substrates on these parameters was investigated. The analysis showed that the preferential orientation of films was dependent on the substrate type.

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15

Jones, K. M., Y. Yan, F. S. Hasoon, and M. M. Al-Jassim. "Transmission Electron Microscopy Study of the Microstructure of Np- Etched CdTe Thin Films." Microscopy and Microanalysis 7, S2 (August 2001): 558–59. http://dx.doi.org/10.1017/s1431927600028865.

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Polycrystalline CdTe is a promising candidate for solar cells due to its nearly ideal band-gap, high absorption coefficient, and ease of film fabrication. Small-area CdTe/CdS cells with efficiencies of 16.0% have been demonstrated. The structure of a typical CdTe/CdS solar cell (Figure 1) consists of a glass superstrate, on which a thin layer of SnO2 is deposited (front contact), n-type CdS, p-type CdTe, and a back contact. Prior to applying the back contact to the CdTe, etching of the CdTe surface using a mixture of nitric and phosphoric (NP) acids is normally needed. It is known that the etching depletes a crystalline CdTe surface of Cd and creates a Te-rich layer. Two effects of the Te-rich layer has been proposed, namely, forming a Te-CdTe low-series-resistance contact and improving CdTe device stability by the gettering of Cu. Thus, the NP etching is an important process in the CdTe device fabrication. in this paper, we report on transmission electron microscopy (TEM) study of the microstructure of the surface of NP etched CdTe thin films.

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16

Zeng, Guanggen, Xia Hao, Shengqiang Ren, Lianghuan Feng, and Qionghua Wang. "Application of ALD-Al2O3 in CdS/CdTe Thin-Film Solar Cells." Energies 12, no. 6 (March 22, 2019): 1123. http://dx.doi.org/10.3390/en12061123.

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The application of thinner cadmium sulfide (CdS) window layer is a feasible approach to improve the performance of cadmium telluride (CdTe) thin film solar cells. However, the reduction of compactness and continuity of thinner CdS always deteriorates the device performance. In this work, transparent Al2O3 films with different thicknesses, deposited by using atomic layer deposition (ALD), were utilized as buffer layers between the front electrode transparent conductive oxide (TCO) and CdS layers to solve this problem, and then, thin-film solar cells with a structure of TCO/Al2O3/CdS/CdTe/BC/Ni were fabricated. The characteristics of the ALD-Al2O3 films were studied by UV–visible transmittance spectrum, Raman spectroscopy, and atomic force microscopy (AFM). The light and dark J–V performances of solar cells were also measured by specific instrumentations. The transmittance measurement conducted on the TCO/Al2O3 films verified that the transmittance of TCO/Al2O3 were comparable to that of single TCO layer, meaning that no extra absorption loss occurred when Al2O3 buffer layers were introduced into cells. Furthermore, due to the advantages of the ALD method, the ALD-Al2O3 buffer layers formed an extremely continuous and uniform coverage on the substrates to effectively fill and block the tiny leakage channels in CdS/CdTe polycrystalline films and improve the characteristics of the interface between TCO and CdS. However, as the thickness of alumina increased, the negative effects of cells were gradually exposed, especially the increase of the series resistance (Rs) and the more serious “roll-over” phenomenon. Finally, the cell conversion efficiency (η) of more than 13.0% accompanied by optimized uniformity performances was successfully achieved corresponding to the 10 nm thick ALD-Al2O3 thin film.

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17

ALY, S. A., D. ABDELMONEM, M. ABDEL-RAHMAN, E. YOUSEF, and E. R. SHAABAN. "STRUCTURAL, OPTICAL CONSTANTS AND ENERGY GAP TUNABILITY WHEN INCORPORATING Te INTO CdSe THIN FILM FOR SOLAR CELLS." Chalcogenide Letters 17, no. 6 (June 2020): 301–13. http://dx.doi.org/10.15251/cl.2020.176.301.

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In the present work, polycrystalline materials of CdSe1-xTex with (x = 0, 0.2, 0.4, 0.6, 0.8 and 1 at. %) were prepared by a conventional solid-state reaction method. Thin films of CdSe1-xTex of about 0.5 µm have been produced using evaporation method. The prepared thin films were characterized by using EDAX and X-ray diffractometer. The Xray diffraction studies shows that the films are polycrystalline in nature, and well oriented along a preferred direction of (002) for hexagonal and along (111) for cubic crystal structure. Both of optical constants (n, k) and film thickness have been determined precisely in terms of envelop method. Analysis of the optical absorption data showed that the transition mechanism takes place by a direct transition. The band gap decreases from 1.677 eV (CdSe) with an increase in Te concentration passing through a minimum of 1.412 eV for CdSe0.4Te0.6 (x = 0.6) and then for higher Te concentration band gap increases to 1.486 eV corresponds to pure CdTe. The importance of CdSe1-xTex compound is the tunability of band gap when incorporating Te into the CdSe. The dispersion of the refractive index is described using the Wimple–DiDomenico (WDD) single oscillator model. The non-linear refractive index has been discussed.

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18

Miyake, Masao, Takashi Sugiura, and Tetsuji Hirato. "Preparation of Polycrystalline CdTe Films by Annealing of Amorphous Films Electrodeposited from Ammoniacal Alkaline Baths." High Temperature Materials and Processes 31, no. 4-5 (October 30, 2012): 553–57. http://dx.doi.org/10.1515/htmp-2012-0092.

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AbstractA new route to prepare polycrystalline CdTe films using electrodeposition of amorphous Cd-Te films and subsequent annealing was investigated. Amorphous Cd-Te films with Te-rich compositions could be electrodeposited from ammoniacal alkaline aqueous solutions. The deposition rate of the amorphous film was much higher than that of crystalline CdTe. Annealing of the Te-rich amorphous Cd-Te film at 400 °C in air yielded a crystallized CdTe film with a nearly stoichiometric composition. Thermodynamic calculations of the vapor pressures of Cd and Te species suggested that the decrease in the Te content of the annealed film was due to the vaporization of Te in the forms of oxides. Although an isothermal annealing generated a number of large holes in the film, an annealing with a slow temperature ramp resulted in a crystalline CdTe film without the large holes.

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19

Shen, Kai, Zhizhong Bai, Yi Deng, Ruilong Yang, Dezhao Wang, Qiang Li, and Deliang Wang. "High efficiency CdTe solar cells with a through-thickness polycrystalline CdTe thin film." RSC Advances 6, no. 57 (2016): 52326–33. http://dx.doi.org/10.1039/c6ra07201a.

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20

Gaur, Shailendra Kumar, and R. S. Mishra. "Thermal Evaporation and microstructure study of CdTe." International Journal of Advance Research and Innovation 3, no. 2 (2015): 187–95. http://dx.doi.org/10.51976/ijari.321534.

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Thin films of CdTe deposited by thermal evaporation at evaporation rate of 1000Å thickness on Si substrate.Deposited thin filmthickness is optimized with vacuum deposition conditions by comparing film thickness value from in-process quartz crystal(piezoelectric transducer) with stylus operated dektek surface profiler.CdTe film of thickness 1000 Åhasbeen deposited on silicon substrate by vacuum evaporation method. The thin films are characterized and properties of deposited film depend upon the deposition rate, geometrical position of substrate from the source and surface condition of the silicon substrate. X-ray diffraction (XRD) studyshows that CdTe films are polycrystalline with preferential orientation of (111) plane in cubic phase for 1, 5 10 Å/sec deposition rates.Energy dispersive X-ray analysis of CdTe films at 1, 5 10 Å/sec deposition rates after quantification gives Te/Cd ratio of 0.98, 1.14 and 1.18 respectively. Scanning electron microscopy (SEM)micrographs of CdTeat different magnifications show grain size in the range of 19-25, 21-28 17-20 nm for deposition rates of 1, 5 10 Å/sec respectively along the grain boundaries. SEM micrograph at deposition rate of 10 Å/sec has smaller size, smooth, void-free and uniformly distributed over the surface of substrate than the other deposition rates.

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21

Powalla, Michael, and Dieter Bonnet. "Thin-Film Solar Cells Based on the Polycrystalline Compound Semiconductors CIS and CdTe." Advances in OptoElectronics 2007 (September 17, 2007): 1–6. http://dx.doi.org/10.1155/2007/97545.

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Анотація:

Thin-film photovoltaic modules based on Cu-In-Ga-Se-S (CIS) and CdTe are already being produced with high-quality and solar conversion efficiencies of around 10%, with values up to 14% expected in the near future. The integrated interconnection of single cells into large-area modules of 0.6×1.2m2 enables low-cost mass production, so that thin-film modules will soon be able to compete with conventional silicon-wafer-based modules. This contribution provides an overview of the basic technologies for CdTe and CIS modules, the research and development (R&D) issues, production technology and capacities, the module performance in long-term outdoor testing, and their use in installations.

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22

Van Gheluwe, Jochen, Jorg Versluys, Dirk Poelman, and Paul Clauws. "Photoluminescence study of polycrystalline CdS/CdTe thin film solar cells." Thin Solid Films 480-481 (June 2005): 264–68. http://dx.doi.org/10.1016/j.tsf.2004.11.031.

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23

Van Calster, A., A. Vervaet, I. De Rycke, J. De Baets, and J. Vanfleteren. "Polycrystalline CdSe films for thin film transistors." Journal of Crystal Growth 86, no. 1-4 (January 1988): 924–28. http://dx.doi.org/10.1016/0022-0248(90)90826-7.

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24

Hou, Juan, Hai Bin Cao, Xu Chu Huang, and Chun Yan Song. "EDS, XRD and Raman Scattering Study of Dy Ion Implanted CdTe Polycrystalline Thin Films." Advanced Materials Research 213 (February 2011): 157–60. http://dx.doi.org/10.4028/www.scientific.net/amr.213.157.

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Dysprosium (Dy) ion implanted CdTe polycrystalline thin film (PTF) deposited on the ceramic substrate by the close spaced sublimation （CSS) method. Both the energy dispersive X-ray spectrometer（EDS）and Raman scattering analysis show that the as-deposited and Dy ion implanted CdTe PTF are non-stoichiometric with excess telluride. Furthermore, X-ray diffraction study reveals that the CdTe PTF forms a zinc-blended structure. In the Raman scattering analysis, the position of the peak on implantation does not change apparently whereas the intensity of the peak decreases owing to the lattice damage and increases as a result of thermal annealing. The data support that Raman activity is enhanced after Dy ion implantation.

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25

Nowell, Matthew M., Michael A. Scarpulla, Naba R. Paudel, Kristopher A. Wieland, Alvin D. Compaan, and Xiangxin Liu. "Characterization of Sputtered CdTe Thin Films with Electron Backscatter Diffraction and Correlation with Device Performance." Microscopy and Microanalysis 21, no. 4 (June 16, 2015): 927–35. http://dx.doi.org/10.1017/s143192761500077x.

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AbstractThe performance of polycrystalline CdTe photovoltaic thin films is expected to depend on the grain boundary density and corresponding grain size of the film microstructure. However, the electrical performance of grain boundaries within these films is not well understood, and can be beneficial, harmful, or neutral in terms of film performance. Electron backscatter diffraction has been used to characterize the grain size, grain boundary structure, and crystallographic texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with microstructure. Weak fiber textures were observed in the as-deposited films, with (111) textures present at lower deposition pressures and (110) textures observed at higher deposition pressures. The CdCl2-treated samples exhibited significant grain recrystallization with a high fraction of twin boundaries. Good correlation of solar cell efficiency was observed with twin-corrected grain size while poor correlation was found if the twin boundaries were considered as grain boundaries in the grain size determination. This implies that the twin boundaries are neutral with respect to recombination and carrier transport.

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26

Di Lalla, Nicolás, Rodolfo A. Pérez, and Fanny Dyment. "Au Diffusion in Polycrystalline CdTe Thin Films." Defect and Diffusion Forum 194-199 (April 2001): 755–60. http://dx.doi.org/10.4028/www.scientific.net/ddf.194-199.755.

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27

Bosio, Alessio, Nicola Romeo, Samantha Mazzamuto, and Vittorio Canevari. "Polycrystalline CdTe thin films for photovoltaic applications." Progress in Crystal Growth and Characterization of Materials 52, no. 4 (December 2006): 247–79. http://dx.doi.org/10.1016/j.pcrysgrow.2006.09.001.

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28

Li, H., X. X. Liu, Y. S. Lin, B. Yang, and Z. M. Du. "Enhanced electrical properties at boundaries including twin boundaries of polycrystalline CdTe thin-film solar cells." Physical Chemistry Chemical Physics 17, no. 17 (2015): 11150–55. http://dx.doi.org/10.1039/c5cp00564g.

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The effect of grain boundaries (GBs), in particular twin boundaries (TBs), on CdTe polycrystalline thin films is studied by conductive atomic force microscopy (C-AFM), electron-beam-induced current (EBIC), scanning Kelvin probe microscopy (SKPM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM).

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29

Dalchiele, E. A., and S. Bonilla. "Electrodeposition of CdTe Polycrystalline Thin Films: Influence of Electroyte Anions in Film Composition." Journal Of The Brazilian Chemical Society 3, no. 3 (1992): 95–97. http://dx.doi.org/10.5935/0103-5053.19920020.

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30

Okamoto, Tamotsu, Shigeyuki Ikeda, Satsuki Nagatsuka, Ryoji Hayashi, Kaoru Yoshino, Yohei Kanda, Akira Noda, and Ryuichi Hirano. "Effects of Antimony Doping in Polycrystalline CdTe Thin-Film Solar Cells." Japanese Journal of Applied Physics 51 (October 22, 2012): 10NC12. http://dx.doi.org/10.1143/jjap.51.10nc12.

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31

Okamoto, Tamotsu, Shigeyuki Ikeda, Satsuki Nagatsuka, Ryoji Hayashi, Kaoru Yoshino, Yohei Kanda, Akira Noda, and Ryuichi Hirano. "Effects of Antimony Doping in Polycrystalline CdTe Thin-Film Solar Cells." Japanese Journal of Applied Physics 51, no. 10S (October 1, 2012): 10NC12. http://dx.doi.org/10.7567/jjap.51.10nc12.

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32

ABOU-ELFOTOUH, F. A., and T. J. COUTTS. "RF PLANAR MAGNETRON SPUTTERING OF POLYCRYSTALLINE CdTe THIN-FILM SOLAR CELLS." International Journal of Solar Energy 12, no. 1-4 (January 1992): 223–31. http://dx.doi.org/10.1080/01425919208909764.

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33

Bosio, A., M. Sozzi, D. Menossi, S. Selleri, A. Cucinotta, and N. Romeo. "Polycrystalline CdTe thin film mini-modules monolithically integrated by fiber laser." Thin Solid Films 562 (July 2014): 638–47. http://dx.doi.org/10.1016/j.tsf.2014.04.059.

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34

Halliday, D. P., J. M. Eggleston, and K. Durose. "A photoluminescence study of polycrystalline thin-film CdTe/CdS solar cells." Journal of Crystal Growth 186, no. 4 (March 1998): 543–49. http://dx.doi.org/10.1016/s0022-0248(97)00819-1.

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35

Journal, Baghdad Science. "Preparation of superposed thin film (CdTe)1-xSex / ZnS and Studying the Effect of Concentration on Some its Electrical Properties." Baghdad Science Journal 11, no. 2 (June 1, 2014): 584–89. http://dx.doi.org/10.21123/bsj.11.2.584-589.

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Preparation of superposed thin film (CdTe)1-xSex / ZnS) with concentration of (x= 0.1, 0.3, 0.5) at a temperature of substrate (Ts= 80 0C) by using Thermal Vacuum Evaporation System. The measurement of X-ray diffraction shows that the compounds CdTe, ZnS, (CdTe)1-xSex and (CdTe)1-xSex / ZnS have a polycrystalline structure, the C-V characteristic shows that the capacitance degrease by increasing the concentration (x) in reverse bias, while the I-V characteristic shows the current dark (Id) increase in forward and reverse bias by increasing (x) and the photocurrent (Iph) increase in reverse bias by increasing the concentration (x), the values of photocurrent are greater than from the values of the dark current for all concentrations.

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36

Tariq, G. H., and M. Anis-ur-Rehman. "Characterization of Physical Properties of Thermally Evaporated Doped CdS Thin Films for Photovoltaics." Key Engineering Materials 510-511 (May 2012): 156–62. http://dx.doi.org/10.4028/www.scientific.net/kem.510-511.156.

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Polycrystalline thin films of Cadmium Sulfide (CdS) have been extensively studied for application as a window layer in CdTe/CdS and CIGS/CdS thin film solar cells. Higher efficiency of solar cells is possible by a better conductivity of a window layer, which can be achieved by doping these films with suitable elements. CdS thin films were deposited on properly cleaned glass substrate by thermal evaporation technique under vacuum2×10-5mbar. Films were structurally characterized by using X-ray diffraction. The X-ray diffraction spectra showed that the thin films were polycrystalline in nature. Aluminum was doped chemically in as deposited and annealed thin films by immersing films in AlNO33.9H2O solutions respectively. Comparison between the effects of different doping ratios on the structural and optical properties of the films was investigated. Higher doping ratios have improved the electrical properties by decreasing the resistivity of the films and slightly changed the bandgap energy Eg. The grain size, strain, and dislocation density were calculated for as-deposited and annealed films.

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37

Amin, Nowshad, M. A. Matin, M. M. Aliyu, M. A. Alghoul, M. R. Karim, and K. Sopian. "Prospects of Back Surface Field Effect in Ultra-Thin High-Efficiency CdS/CdTe Solar Cells from Numerical Modeling." International Journal of Photoenergy 2010 (2010): 1–8. http://dx.doi.org/10.1155/2010/578580.

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Polycrystalline CdTe shows greater promises for the development of cost-effective, efficient, and reliable thin film solar cells. Results of numerical analysis using AMPS-1D simulator in exploring the possibility of ultrathin, high efficiency, and stable CdS/CdTe cells are presented. The conventional baseline case structure of CdS/CdTe cell has been explored with reduced CdTe absorber and CdS window layer thickness, where 1 μm thin CdTe and 50 nm CdS layers showed reasonable efficiencies over 15%. The viability of 1 μm CdTe absorber layer together with possible back surface field (BSF) layers to reduce minority carrier recombination loss at the back contact in ultra thin CdS/CdTe cells was investigated. Higher bandgap material like ZnTe and low bandgap materials like Sb2Te3and As2Te3as BSF were inserted to reduce the holes barrier height in the proposed ultra thin CdS/CdTe cells. The proposed structure of SnO2/Zn2SnO4/CdS/CdTe/As2Te3/Cu showed the highest conversion efficiency of 18.6% (Voc= 0.92 V,Jsc= 24.97 mA/cm2, and FF = 0.81). However, other proposed structures such as SnO2/Zn2SnO4/CdS/CdTe/Sb2Te3/Mo and SnO2/Zn2SnO4/CdS/CdTe/ZnTe/Al have also shown better stability at higher operating temperatures with acceptable efficiencies. Moreover, it was found that the cells normalized efficiency linearly decreased with the increased operating temperature with relatively lower gradient, which eventually indicates better stability of the proposed ultra thin CdS/CdTe cells.

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38

Journal, Baghdad Science. "Study the effect of thickness and annealing temperature on the Electrical Properties of CdTe thin Films." Baghdad Science Journal 5, no. 3 (September 7, 2008): 449–53. http://dx.doi.org/10.21123/bsj.5.3.449-453.

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The electrical properties of polycrystalline cadmium telluride thin films of different thickness (200,300,400)nm deposited by thermal evaporation onto glass substrates at room temperature and treated at different annealing temperature (373, 423, 473) K are reported. Conductivity measurements have been showed that the conductivity increases from 5.69X10-5 to 0.0011, 0.0001 (?.cm)-1 when the film thickness and annealing temperature increase respectively. This increasing in ?d.c due to increasing the carrier concentration which result from the excess free Te in these films.

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39

Zeng Guang-Gen, Zheng Jia-Gui, Li Bing, Lei Zhi, Wu Li-Li, Cai Ya-Ping, Li Wei, Zhang Jing-Quan, Cai Wei, and Feng Liang-Huan. "Polycrystalline CdS/CdTe thin-film solar cells with intrinsic SnO2 films of high resistance." Acta Physica Sinica 55, no. 9 (2006): 4854. http://dx.doi.org/10.7498/aps.55.4854.

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40

Ariswan. "Structural, Chemical Composition and Optical Properties of CdTe Fabricated by Vacuum Evaporation Technique." Advanced Materials Research 896 (February 2014): 497–501. http://dx.doi.org/10.4028/www.scientific.net/amr.896.497.

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CdTe polycrystalline thin films have been fabricated by vacuum evaporation technique. Their properties have been investigated using X-ray diffraction, energy dispersive spectroscopy, scanning electron microscope and uv-vis spectroscopy. The results showed that the CdTe thin films crystalized at hexagonal structure with lattice parametersaandc6.45 Å and 7.66 Å respectively. The EDS results showed that the chemical composition is nonstoichiometry, slightly rich of Tellerium with Cd/Te of 0,9. It has a uniform shape with color homogenity and has an optical band gap at room temperature about 1.47 eV. Keywords:Vacuum evaporation, polycrystalline, cadmium telluride, thin films.

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41

Zeng, Guanggen, Jingquan Zhang, Wenwu Wang, and Lianghuan Feng. "Correlation of Interfacial Transportation Properties of CdS/CdTe Heterojunction and Performance of CdTe Polycrystalline Thin-Film Solar Cells." International Journal of Photoenergy 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/519386.

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The light and dark output performances of CdS/CdTe solar cells made by close-spaced sublimation (CSS) were investigated to elucidate the transportation properties of carriers at CdS/CdTe heterojunction interface. It has been found that the interfacial transportation properties were relatively sensitive to variations of the characteristics of heterojunction due to the series resistance and shunting effects. For the high quality cell with 12.1% efficiency, narrow depletion region of ~1.1 microns and large electric field intensity of ~1.3 V/μm allow the sufficient energy-band bending close to CdS layer at CdS/CdTe heterojunction, which changes the carrier transportation mechanism from emission to diffusion and leads to the optimal rectifying characteristics with small dark saturation current density ~6.4 × 10−10 A/cm2. As a result, the schematic diagram of heterojunction band structure corresponding to various performances of solar cells has also been presented.

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42

Rakhmonov, Tokhirbek Imomalievich, Dilkhumor Tolibjonovna Mamadieva, and Nosirjon Khaydarovich Yuldashev. "PHOTOELECTRIC PHENOMENA IN THIN POLYCRYSTALLINE CdTe, CdSe, CdS FILMS UNDER MECHANICAL DEFORMATION." European Science Review, no. 11-12 (2021): 40–49. http://dx.doi.org/10.29013/esr-21-11.12-40-49.

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43

Romeo, N., A. Bosio, R. Tedeschi, and V. Canevari. "Growth of polycrystalline CdS and CdTe thin layers for high efficiency thin film solar cells." Materials Chemistry and Physics 66, no. 2-3 (October 2000): 201–6. http://dx.doi.org/10.1016/s0254-0584(00)00316-3.

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44

Bosio, Alessio, Stefano Pasini, and Nicola Romeo. "The History of Photovoltaics with Emphasis on CdTe Solar Cells and Modules." Coatings 10, no. 4 (April 2, 2020): 344. http://dx.doi.org/10.3390/coatings10040344.

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Among thin-film photovoltaic technology, cadmium telluride (CdTe) has achieved a truly impressive development that can commercially compete with silicon, which is still the king of the market. Solar cells made on a laboratory scale have reached efficiencies close to 22%, while modules made with fully automated in-line machines show efficiencies above 18%. This success represents the result of over 40 years of research, which led to effective and consolidated production processes. Based on a large literature survey on photovoltaics and on the results of research developed in our laboratories, we present the fabrication processes of both CdTe polycrystalline thin-film solar cells and photovoltaic modules. The most common substrates, the constituent layers, their interaction, the interfaces and the different “tricks” necessary to obtain highly efficient devices will be analyzed. A realistic industrial production process will be analytically described. Moreover, environmental aspects, end-of-life recycling and the life cycle assessment of CdTe-based modules will be deepened and discussed.

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45

Kiprotich, Sharon, F. B. Dejene, and Martin O. Onani. "Effects of growth time on the material properties of CdTe/CdSe core/shell nanoparticles prepared by a facile wet chemical route." Materials Research Express 9, no. 2 (February 1, 2022): 025008. http://dx.doi.org/10.1088/2053-1591/ac5073.

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Abstract This study presents a facile synthetic approach used to prepare CdTe/CdSe core/shell nanoparticles (NPs). The effects of reaction time on the material properties of the CdTe/CdSe NPs are reported. It was realized that the reaction time has significant impact on the CdSe shell growth on the CdTe core. Various techniques were used to characterize the as-prepared CdTe/CdSe NPs. The x-ray diffraction (XRD) was used to study the crystal structure and the possible growth of the CdSe shell on the CdTe core. The results obtained indicated the formation of zinc blende crystal structure which was transformed from a polycrystalline to single crystalline structure. The XRD pattern displayed features that are intermediate between the CdTe and CdSe, a sign of shell formation and not two separate compounds formed. This was also supported by high resolution transmission electron microscope images obtained. The crystallite sizes estimated using Scherrer formula were all less than 3 nm showing that the NPs are in quantum confinement regime. Scanning electron microscope was used to determine the surface topography while the energy x-ray dispersive spectrometer displayed the elemental composition of the as-prepared NPs. SEM and HRTEM images showed uniformly distributed spherical NPs with some agglomerations observed at longer duration of synthesis. The optical properties (photoluminescence (PL) and absorbance) investigated at different reaction times (20, 40, 60 and 80 min) presented novel features which show the formation of a thin CdSe shell on the CdTe core NPs. The PL emission wavelength was dramatically red shifted upon the growth of the CdSe shell on the CdTe core (from 541–615 nm). Other unique features of the as-grown CdTe/CdSe NPs are discussed in detail. The obtained results displayed good material properties of the CdTe/CdSe NPs suitable for use in biomaging applications.

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46

McCandless, Brian E. "CdTe Solar Cells: Processing Limits and Defect Chemistry Effects on Open Circuit Voltage." MRS Proceedings 1538 (2013): 249–60. http://dx.doi.org/10.1557/opl.2013.1017.

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ABSTRACTThe role of CdTe solar cell processing on the defect chemistry that limits open circuit voltage (VOC) is addressed in the thermochemical processing regimes commonly encountered in present-generation CdTe devices. The highest VOC is 0.91 V for a bulk CdTe crystal with ITO which is only marginally higher than VOC = 0.86 V obtained for polycrystalline CdTe films with CdS. Both fall ∼0.4 V short of the VOC expected for CdTe, having band gap EG = 1.5 eV. The present >16% efficient superstrate CdTe cell uses a process based on high-temperature, T > 500°C, CdTe growth on CdS, coupled with optimized methods for incorporating oxygen, sulfur, copper, and chloride species in the CdTe film. Pushing cell conversion efficiencies beyond 20% will require increasing VOC beyond 1V. However the present pathway of processing optimization will likely yield VOC and efficiency converging on 0.9 V and <20%, respectively.

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47

Najm, Asmaa Soheil, Hasanain Salah Naeem, Duaa Abdul Rida Musa Alwarid, Abdulwahab Aljuhani, Siti Aishah Hasbullah, Hiba Ali Hasan, Kamaruzzaman Sopian, et al. "Mechanism of Chemical Bath Deposition of CdS Thin Films: Influence of Sulphur Precursor Concentration on Microstructural and Optoelectronic Characterizations." Coatings 12, no. 10 (September 26, 2022): 1400. http://dx.doi.org/10.3390/coatings12101400.

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In this study, we aimed to improve our understanding of the response mechanisms associated with the formation of CdS thin films. CdS thin film remains the most valuable option for many researchers, since it has shown to be an effective buffer material for film-based polycrystalline solar cells (CdTe, CIGSe, CZTS). We performed experimental and numerical simulations to investigate the effect of different thiourea concentrations on the characteristics of the CdS buffer layer. The experimental results reveal that an increase in thiourea concentrations had a direct effect on the optical results, with bandgap values ranging from (2.32 to 2.43) eV. XRD analysis confirmed that all deposited films were polycrystalline, except for [1/0.75], where there is no CdS formation. Electrical studies indicated that CdS with a molar ratio of [Cd]/[S] of 1 had the maximum carrier concentration (3.21 × 1014 cm−3) and lowest resistivity (1843.9 Ω·cm). Based on the proposed mechanism, three kinds of mechanisms are involved in the formation of CdS layers. Among them, the ion-by-ion mechanism has a significant effect on the formation of CdS films. Besides, modelling studies reveal that the optic-electrical properties of the buffer layer play a crucial role in influencing the performance of a CIGS solar cell.

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48

De Baets, J., J. Vanfleteren, I. De Rycke, J. Doutreloigne, A. Van Calster, and P. De Visschere. "High-voltage polycrystalline CdSe thin-film transistors." IEEE Transactions on Electron Devices 37, no. 3 (March 1990): 636–39. http://dx.doi.org/10.1109/16.47767.

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49

Huang, Lei, Yue Zhao, and Dong Cai. "Homojunction and heterojunction based on CdTe polycrystalline thin films." Materials Letters 63, no. 24-25 (October 2009): 2082–84. http://dx.doi.org/10.1016/j.matlet.2009.06.028.

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50

Bonilla, Silvia, and Enrique A. Dalchiele. "Electrochemical deposition and characterization of CdTe polycrystalline thin films." Thin Solid Films 204, no. 2 (October 1991): 397–403. http://dx.doi.org/10.1016/0040-6090(91)90078-c.

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