Download or read book Optimization of Process Parameters for Reduced Thickness CIGSeS Thin Film Solar Cells written by Shirish A. Pethe and published by . This book was released on 2010 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: With further optimization of the reaction process of the absorber layer as well as the other layers higher efficiencies can be achieved. The effect of sodium on the device performance is experimentally verified in this work. To the best of our knowledge the detrimental effect of excess sodium has been verified by experimental data and effort has been made to correlate the variation in PV parameter to theoretical models of effect of sodium. It has been a regular practice to deposit thin barrier layer prior to molybdenum deposition to reduce the micrononuniformities caused due to nonuniform out diffusion of sodium from the soda lime glass. However, it was proven in this work that an optimally thick barrier layer is necessary to reduce the out diffusion of sodium to negligible quantities and thus reduce the micrononuniformities. Molybdenum back contact deposition is a bottleneck in high volume manufacturing due to the current state of art where multi layer molybdenum film needs to be deposited to achieve the required properties. In order to understand and solve this problem experiments were carried out. The effect of working distance (distance between the target and the substrate) on film properties was studied and is presented in this work. During the course of this work efforts were taken to carry out a systematic and detailed study of some of the fundamental issues related to CIGS technology and particular for high volume manufacturing of CIGS PV modules and lay a good foundation for further improvement of PV performance of CIGS thin film solar cells prepared by the two step process of selenization and sulfurization of sputtered metallic precursors.

Download or read book Optimization of Process Parameters for Faster Deposition of CuIn1x Gax S2 and CuIn1x Gax Se2 y Sy Thin Film Solar Cells written by Ashwani Kaul and published by . This book was released on 2012 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film solar cells have the potential to be an important contributor to the world energy demand in the 21st century. Among all the thin film technologies, CuInGaSe2 (CIGS) thin film solar cells have achieved the highest efficiency. However, the high price of photovoltaic (PV) modules has been a major factor impeding their growth for terrestrial applications. Reduction in cost of PV modules can be realized by several ways including choosing scalable processes amenable to large area deposition, reduction in the materials consumption of active layers, and attaining faster deposition rates suitable for in-line processing. Selenization-sulfurization of sputtered metallic Cu-In-Ga precursors is known to be more amenable to large area deposition. Sputter-deposited molybdenum thin film is commonly employed as a back contact layer for CIGS solar cells. However, there are several difficulties in fabricating an optimum back contact layer. It is known that molybdenum thin films deposited at higher sputtering power and lower gas pressure exhibit better electrical conductivity. However, such films exhibit poor adhesion to the soda-lime glass substrate. On the other hand, films deposited at lower discharge power and higher pressure although exhibit excellent adhesion show lower electrical conductivity. Therefore, a multilayer structure is normally used so as to get best from the two deposition regimes. A multi-pass processing is not desirable in high volume production because it prolongs total production time and correspondingly increases the manufacturing cost. In order to make manufacturing compliant with an in-line deposition, it is justifiable having fewer deposition sequences. Thorough analysis of pressure and power relationship of film properties deposited at various parameters has been carried out. It has been shown that it is possible to achieve a molybdenum back contact of desired properties in a single deposition pass by choosing the optimum deposition parameters. It is also shown that the film deposited in a single pass is actually a composite structure. CIGS solar cells have successfully been completed on the developed single layer back contact with National Renewable Energy Laboratory (NREL) certified device efficiencies [greater than]11%. The optimization of parameters has been carried out in such a way that the deposition of back contact and metallic precursors can be carried out in identical pressure conditions which is essential for in-line deposition without a need for load-lock. It is know that the presence of sodium plays a very critical role during the growth of CIGS absorber layer and is beneficial for the optimum device performance. The effect of sodium location during the growth of the absorber layer has been studied so as to optimize its quantity and location in order to get devices with improved performance. NREL certified devices with efficiencies [greater than]12% have been successfully completed.

Download or read book Correlation Between Preparation Parameters and Properties of Molybdenum Back Contact Layer for CIGS Thin Film Solar Cells written by Eigo Takahashi and published by . This book was released on 2010 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sputter-deposited Mo thin films are commonly employed as a back contact layer for CIGS and CuInSe2 (CIS)-based solar cells; however, there are several difficulties in fabricating a qualified back contact layer. Generally, Mo thin films deposited at higher sputtering power and lower working gas pressure tend to exhibit lower resistivity; however, such films have a poor adhesion to the glass substrate. On the other hand, films deposited at lower power and higher gas pressure tend to have a higher resistivity, whereas the films exhibit an excellent adhesion to the glass substrate. Therefore, it has been a practice to employ multi-layered Mo thin film back contact layers to achieve the properties of good adhesion to the glass substrate and low resistivity simultaneously. However, multi layer processes have a lower throughput and higher fabricating cost, and requires more elaborated equipment compared to single layer processes, which are not desirable from the industrial point of view. As can be seen, above mentioned process parameters and the corresponding Mo thin film properties are at the two extreme ends of the spectrum. Hence experiments were conducted to find out the mechanisms which influence the properties of Mo thin films by changing the two process parameters of working gas pressure and sputtering power individually. The relationships between process parameters and above mentioned properties were studied and explained. It was found that by selecting the process parameters properly, less resistive, appropriate-surfaced, and highly adhesive single layer Mo thin films for CIGS solar cells can be achieved.

Download or read book Optimization of Low Cost Processes for Thin C Si Solar Cell Production written by Efrain Ochoa Martinez and published by LAP Lambert Academic Publishing. This book was released on 2014-03 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: As world population grows the total energy demanded increases. The energy from sources like the photovoltaic cells, emerges as a sustainable, environmentally clean and cost competitive option if produced on a large scale. The current trend in photovoltaic industry passes through increasing efficiency and reducing costs of the modules. A significant part of these costs originates in the semiconductor substrate material, therefore, the tendency is to reduce the thickness of the cells; however, the manufacturing processes need to be optimized. The aim is to implement in-line and contact-less techniques which increase productivity while reduce breakage yield. This work presents the results obtained towards that direction, particularly in the field of emitter formation and metallization.

Download or read book Effect of Sodium and Absorber Thickness on CIGS2 Thin Film Solar Cells written by Parag S. Vasekar and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a study of morphology and device properties of CIGS2 thin films with Copper-deficient absorbers after minute amounts of sodium are introduced on the Mo-coated substrate in the form of sodium fluoride layer prior to sputter deposition of copper-gallium alloy and indium. Photovoltaic conversion efficiency of 9.15% was obtained for copper-deficient absorbers. In a parallel set of experiments, copper-rich precursors were used to produce absorbers of lower thickness range values and the parameters were optimized. Photovoltaic conversion efficiency of 10.12% was obtained for an absorber of thickness 1.5 [micrometers] and an efficiency of 9.62% was obtained for an absorber of thickness 1.2 [micrometers].

Download or read book Performance Optimization of Cu In1 x Gax Se1 y Sy 2 Thin film Solar Cells by Characterization and Modelling of Temperature and Low light Behavior written by Hamsa Ahmed and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the impact of structural variations of CIGS solar cells on their temperature coefficients, their stability, and their low light performance is studied. The layer modifications implemented for this study include different buffer, window layers and back contacts materials, and different double graded absorbers with change in their thickness and sodium post deposition treatment. It was demonstrated that the absorber layer exhibits the largest influence on the temperature dependence of the power output amongst all modified layers of the structure. The buffer and the absorber elemental composition showed to play an important role in the elemental interdiffusion and hence led to the creation of amphoteric defects that are light and temperature sensitive. Studies on the impact of different solar cell structures on the shift of the dominant recombination region at different light intensities were also performed.

Download or read book Performance Optimization of Cu In1 x Gax Se1 y Sy 2 Thin film Solar Cells by Characterization and Modelling of Temperature and Low light Behavior written by Hamsa Ahmed and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the impact of structural variations of CIGS solar cells on their temperature coefficients, their stability, and their low light performance is studied. The layer modifications implemented for this study include different buffer, window layers and back contacts materials, and different double graded absorbers with change in their thickness and sodium post deposition treatment. It was demonstrated that the absorber layer exhibits the largest influence on the temperature dependence of the power output amongst all modified layers of the structure. The buffer and the absorber elemental composition showed to play an important role in the elemental interdiffusion and hence led to the creation of amphoteric defects that are light and temperature sensitive. Studies on the impact of different solar cell structures on the shift of the dominant recombination region at different light intensities were also performed.

Download or read book Optimisation of Cu In Ga Se 1tn2 Thin Film Solar Cells and Modules for Low Irradiance Conditions written by Alessandro Virtuani and published by . This book was released on 2004 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metal induced Growth of Microcrystalline Silicon Thin Films for Solar Cells written by and published by . This book was released on 2005 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research focused on the process study for deposition of device quality polycrystalline silicon (poly-Si) thin films and solar cell fabrication by using a novel technique, metal-induced growth (MIG). Cobalt (Co) is introduced in the studies as a seed layer metal for the first time, while nickel (Ni) was another candidate. To grow the poly-Si, Co or Ni seed-layers were deposited on the foreign substrates by thermal evaporation with a few nm to 50 nm thickness. Substrates were transferred into the sputtering system for Si sputtering at elevated temperature from 525°C to 625°C. The Co or Ni reacted with sputtered Si to form metal disilicides which have very small lattice mismatch with Si (0.4% lattice mismatch for NiSi2 and Si, 1.2% lattice mismatch for CoSi2 and Si). The crystalline metal disilicides provide nucleation sites for poly-Si growth. With metal-induced growth, the relatively large-grain poly-Si films can be produced at relatively low temperatures on the various foreign substrates. Compared with Ni induced Si films, Co induced poly-Si has longer minority lifetime of 0.46 [mu]s as deposited and 1.3 [mu]s after annealing. A two-step sputtering method used for film deposition showed superiority over single step sputtering by achieving Si films with larger grain size (over 1 [mu]m) and less contamination. A double seed layer (5nm Co/50nm Ni) method was developed to produce the Si film with less Ni diffusion into Si. Metal-induced Si films were deposited on flexible thin tungsten substrates for solar cell fabrication. The good back Ohmic contact (metal disilicide) was formed naturally when the Si film was deposited. In this work, the solar cells were fabricated successfully by using metal-induced grown poly-Si. With the fabricated Schottky and P/N junction solar cells, the metal-induced growth processing parameters were studied. It was found that low-pressure sputtering, oxygen control during film growth, post-annealing and Si film hydrogenation are important to produce high quality poly-Si with fewer defects. The Schottky solar cell with optimized processing parameters showed the J[sub]sc and V[sub]oc of 12 mA/cm2 and 0.2 V, respectively. By passivating the MIG [mu]c-Si surface with hydrogenated nanocrystalline Si (nc-Si:H), the V[sub]oc was improved to 0.31 V. In addition, the current transport mechanism in Schottky and P/N junction devices were studied for different film growth conditions. The results showed that two-step sputtering, oxygen control and hydrogenation improved the quality of the Si film and devices.

Download or read book Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices written by Robert Birkmire and published by . This book was released on 2003 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation of High Efficiency Cu2ZnSn S Se 4solar Cells Based on a Single step Sulfo selenization Process written by Haibing Xie and published by . This book was released on 2016 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cu2ZnSn(S, Se)4 (CZTSSe) kesterite semiconductors have been proposed as a potential medium to long term replacement of Cu(In, Ga)(S, Se)2 (CIGS) chalcopyrites for sustainable cost-efficient thin film technologies compatible with mass deployment at Terawatt level, being only constituted by elements abundant in the earth crust in contrast with the scarce Indium in CIGS. In this thesis, high efficiency CZTSSe solar cells were fabricated based on a single-step sulfo-selenization process. CZTSSe absorbers with optimal S/(S+Se) ratio, minimized Zn(S, Se) secondary phases in the interfaces, and good crystal quality were achieved through systematically fine tuning of various processing parameters during thermal treatments. The thermodynamic equilibrium of the single-step sulfo-selenization process was also analysed to elucidate the impact of different parameters on the thin films S/(S+Se) ratio. Besides, to address the big challenge of secondary phases in CZTSSe solar cells, an innovative (NH4)2S etching was developed for the selective and effective removal of Sn-(S, Se) secondary phases. This (NH4)2S etching can also passivate the absorber surface and a passivation mechanism was proposed to explain this behaviour. To further improve the efficiency of the CZTSSe solar cells, the CZTSSe/CdS interface was focused and engineered. Na spatial distribution in the CZTSSe/CdS interface region was optimized by a post low temperature treatment process (PLTT), leading to considerable enhancement of the performance of CZTSSe solar cells. An innovative Na dynamics model was established to illustrate the Na in-depth profiles. In addition, Cu doped CdS was investigated to reduce the thickness of CdS while keeping the comparable performance of the kesterite devices, which provides new possibilities to address the Cd concern. Finally, to suppress the CZTSSe/CdS interface recombination and reduce the Voc deficit of the CZTSSe solar cells, a facile wet chemical route based on AlCl3/GaCl3 + thioacetamide solutions were developed. The Voc and efficiency improvement after the chemical treatments can be mainly ascribed to the decrease of interface recombination and shunt paths. A champion CZTSSe solar cell with 9.1% efficiency and FF over 69% was achieved after all these processing optimizations (no ARC). This demonstrates that the single-step sulfo-selenization methodology is promising and feasible for obtaining high efficiency CZTSSe solar cells. selenization methodology is promising and feasible for obtaining high efficiency CZTSSe solar cells.

Download or read book Fabrication and Analysis of CIGS Nanoparticle based Thin Film Solar Cells written by Parvin Ghane and published by . This book was released on 2012 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fabrication and analysis of Copper Indium Gallium di-Selenide (CIGS) nanoparticles-based thin film solar cells are presented and discussed. This work explores non-traditional fabrication processes, such as spray-coating for the low-cost and highly-scalable production of CIGS-based solar cells. CIGS nanoparticles were synthesized and analyzed, thin CIGS films were spray-deposited using nanoparticle inks, and resulting films were used in low-cost fabrication of a set of CIGS solar cell devices. This synthesis method utilizes a chemical colloidal process resulting in the formation of nanoparticles with tunable band gap and size. Based on theoretical and experimental studies, 100 nm nanoparticles with an associated band gap of 1.33 eV were selected to achieve the desired film characteristics and device performances. Scanning electron microcopy ΔΚ� αλγ πζφδ κδαπροδκδλϟ ζλπϟορκδλϟπ �Φδϟαπζφδο� ςδοδ ρπδγ ϟμ πϟργυ ϟϝδ πζφδ αλγ πϝανδ με ϟϝδ λαλμναοϟζϐιδπ� Διδϐϟομλ γζπνδοπζσδ πνδϐϟομπϐμνυ �ΔΓΠ� οδπριϟπ ϐμλεζοκδγ ϟϝδ νοδπδλϐδ με ϟϝδ εμρο διδκδλϟπ� �μννδο ��ρ�� Ζλγζρκ �Ζλ�� Ϛαιιζρκ �Ϛα�� αλγ Πδιδλζρκ �Πδ� ζλ ϟϝδ πυλϟϝδπζφδγ λαλμναοϟζϐιδπ� ςϝζιδ Τ�οαυ γζεεοαϐϟζμλ �ΤΟΓ� οδπριϟπ ϐμλεζοκδγ ϟϝδ ϟδϟοαϛμλαι ϐϝαιϐμνυοζϟδ ϐουπϟαι πϟορϐϟροδ� Ϟϝδ ριϟοασζμιδϟ�σζπζβιδ�λδαο ζλεοα�οδγ �ΡΣ�Σζπ�ΛΖΟ� πνδϐϟομνϝμϟμκδϟου οδπριϟπ με ϟϝδ λαλμναοϟζϐιδπ γδνζϐϟδγ ιζϛϝϟ αβπμοβαλϐδ ϐϝαοαϐϟδοζπϟζϐπ ςζϟϝ ϛμμγ μσδοιαν αϛαζλπϟ ϟϝδ πμιαο ζοοαγζαλϐδ πνδϐϟορκ� Ϟϝδ γδνμπζϟζμλπ με ϟϝδ λαλμναοϟζϐιδπ ςδοδ νδοεμοκδγ ρπζλϛ πνοαυ�ϐμαϟζλϛ ϟδϐϝλζξρδπ� Λαλμναοϟζϐιδ ζλθ γζπνδοπδγ ζλ δϟϝαλμι ςαπ πνοαυδγ ρπζλϛ α πζκνιδ αζοβορπϝ ϟμμι� Ϟϝδ ϟϝζϐθλδππδπ με ϟϝδ γδνμπζϟδγ εζικπ ςδοδ ϐμλϟομιιδγ ϟϝομρϛϝ σαοζαϟζμλπ ζλ ϟϝδ γδνμπζϟζμλ πϟδνπ� πρβπϟοαϟδ ϟμ πνοαυ�λμφφιδ γζπϟαλϐδ� πζφδ με ϟϝδ λμφφιδ� αλγ αζο νοδππροδ� Προεαϐδ εδαϟροδπ αλγ ϟμνμιμϛυ με ϟϝδ πνοαυ�γδνμπζϟδγ εζικπ ςδοδ αλαιυφδγ ρπζλϛ αϟμκζϐ εμοϐδ κζϐομπϐμνυ �ΑΕΚ�� Ϟϝδ γδνμπζϟδγ εζικπ ςδοδ μβπδοσδγ ϟμ βδ οδιαϟζσδιυ ρλζεμοκ ςζϟϝ α κζλζκρκ ϟϝζϐθλδππ με ʹ«« λκ� Νμπϟ�αλλδαιζλϛ με ϟϝδ εζικπ αϟ σαοζμρπ ϟδκνδοαϟροδπ ςαπ πϟργζδγ εμο ϟϝδ νϝμϟμδιδϐϟοζϐ νδοεμοκαλϐδ με ϟϝδ γδνμπζϟδγ εζικπ� �ροοδλϟ γδλπζϟυ αλγ σμιϟαϛδ �Η�Σ� ϐϝαοαϐϟδοζπϟζϐπ ςδοδ κδαπροδγ ρλγδο ιζϛϝϟ ζιιρκζλαϟζμλ αεϟδο αλλδαιζλϛ αϟ γζεεδοδλϟ ϟδκνδοαϟροδπ� Ζϟ ςαπ μβπδοσδγ ϟϝαϟ ϟϝδ ϝζϛϝδπϟ νϝμϟμδιδϐϟοζϐ δεεδϐϟ οδπριϟδγ ζλ αλλδαιζλϛ ϟδκνδοαϟροδπ με »͵«�“͵« γδϛοδδ ϐδλϟζϛοαγδ ρλγδο αζο αϟκμπνϝδοδ� Ϟϝδ γδσδιμνδγ �ΖϚΠ εζικπ ςδοδ ζκνιδκδλϟδγ ζλ πμιαο ϐδιι γδσζϐδπ ϟϝαϟ ζλϐιργδγ �αγκζρκ Πριεζγδ ��γΠ� αλγ Φζλϐ Μτζγδ �ΦλΜ� ιαυδοπ� Ϟϝδ �γΠ εζικ πδοσδγ απ ϟϝδ λ�ϟυνδ ιαυδο ϟμ εμοκ α νλ ηρλϐϟζμλ ςζϟϝ ϟϝδ ν�ϟυνδ �ΖϚΠ ιαυδο� Ζλ α ϟυνζϐαι γδσζϐδ� α ”«« λκ �γΠ ιαυδο ςαπ γδνμπζϟδγ ϟϝομρϛϝ ϐϝδκζϐαι βαϟϝ γδνμπζϟζμλ μλ α » �ơκ ϟϝζϐθ �ΖϚΠ εζικ� Α ϟϝζλ ιαυδο με ζλϟοζλπζϐ ΦλΜ ςαπ πνοαυ ϐμαϟδγ μλ ϟϝδ �γΠ εζικ ϟμ νοδσδλϟ πϝμοϟζλϛ ςζϟϝ ϟϝδ ϟμν ϐμλγρϐϟμο ιαυδο� »�͵ �ơκ πνοαυ�γδνμπζϟδγ αιρκζλρκ γμνδγ ΦλΜ ιαυδο� Α πδϟ με εαβοζϐαϟδγ γδσζϐδπ ςδοδ ϟδπϟδγ ρπζλϛ α Θδζϟϝιδυ πδκζϐμλγρϐϟμο ϐϝαοαϐϟδοζφαϟζμλ ζλπϟορκδλϟ αλγ κζϐομκαλζνριαϟμο νομβδ πϟαϟζμλ� Ϟϝδ ϝζϛϝδπϟ κδαπροδγ γδσζϐδ δεεζϐζδλϐυ ςαπ »�ʹ��̓ Ϟϝδ ϐμλπζγδοδγ πμιαο ϐδιι γδσζϐδπ ςδοδ πζκριαϟδγ ζλ ΑΓΔΝϞ “�« πμιαο ϐδιι πζκριαϟμο βαπδγ μλ ϟϝδ ϛζσδλ εαβοζϐαϟζμλ αλγ δτνδοζκδλϟαι ναοακδϟδοπ� Ϟϝδ πζκριαϟζμλ κμγριδ γδσδιμνδγ ςαπ πρϐϐδππεριιυ ϐαιζβοαϟδγ ςζϟϝ ϟϝδ δτνδοζκδλϟαι οδπριϟπ� Ϟϝζπ κμγριδ ϐαλ βδ ρπδγ εμο ερϟροδ γδσδιμνκδλϟ με ϟϝδ ϛζσδλ ςμοθ�

Download or read book Optimization of Film Morphology for the Performance of Organic Thin Film Solar Cells written by Eric S. Muckley and published by . This book was released on 2013 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The power conversion efficiency of organic thin film solar cells must be improved before they can become commercially competitive alternatives to silicon-based photovoltaics. Exciton diffusion and charge carrier migration in organic films are strongly influenced by film morphology, which can be controlled by the substrate temperature during film growth. Zinc-phthalocyaninelbuckminsterfullerene bilayer film devices are fabricated with substrate temperatures between 25 C and 224 C and their solar cell performance is investigated here. The device open-circuit voltage, efficiency, and fill factor all exhibit peaks when films are grown at temperatures between 160 C and 180 C, which is likely a result of both the increase in shunt resistance and reduction in undesirable back diode effects which occur between l00 C and 180 C. The device performance can also be attributed to changes in the film crystallite size, roughness, and abundance of pinholes, as well as the occurrence of crystalline phase transitions which occur in both zinc-phthalocyanine and buckminsterfullerene between 150 C and 200 C. The unusually high open-circuit voltage (1.2 V), low short-circuit current density (0.03 mA/cm 2), and low device efficiency (0.04%) reported here are reminiscent of single layer phthalocyanine-based Schottky solar cells, which suggests that pinholes in bilayer film devices can effectively lead to the formation of Schottky diodes.

Download or read book Optimization and Characterization of Transparent Oxide Layers for CIGS Solar Cells Fabrication written by Qiudi Liu and published by . This book was released on 2007 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we studied the structural, electrical, and optical properties of three different transparent oxides compounds in their thin film forms. These three compounds were aluminum doped zinc oxide (ZnO:Al), indium tin oxide (ITO) and intrinsic zinc oxide (ZnO). These films are a critical part of Cu(In,Ga)Se2 solar cells, as they play the role of the front contact collecting the photo-generated carriers while letting the photons penetrate into the active semiconductor layers. The films were deposited by radio frequency (r.f.) magnetron sputtering on soda lime glass. We investigated the change of the thin film properties in terms of the main deposition parameters: deposition pressure, substrate temperature, and target r.f. power. Similar trends were found for ZnO:Al and ITO, which were correlated with results from the literature. The optical band gap and the conductivity tend to decrease for increased deposition pressure, while they increase for increased substrate temperature or target power. The crystallinity and the surface roughness tend to increase for an increase of all three parameters, even if some parabolic shapes are obtained for some of the properties. For the ZnO films, the optical band gap and the conductivity do not change with the deposition pressure, substrate temperature or target power, while the crystallinity and the surface roughness tend to increase. These results were correlated with references from other research group

Download or read book A NOVEL LOW THERMAL BUDGET THIN FILM POLYSILICON FABRICATION PROCESS FOR LARGE AREA HIGH THROUGHPUT SOLAR CELL PRODUCTION written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel thin-film poly-Si fabrication process has been demonstrated. This low thermal budget process transforms the single- and multi-layer amorphous silicon thin films into a poly-Si structure in one simple step over a pulsed rapid thermal annealing process with the enhancement of an ultrathin Ni layer. The complete poly-Si solar cell was fabricated in a short period of time without deteriorating the underneath glass substrate. The unique vertical crystallization process including the mechanism is discussed. Influences of the dopant type and process parameters on crystal structure will be revealed. The poly-Si film structure has been proved using TEM, XRD, Raman, and XPS methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.

Download or read book Effect of Heat Treatments and Reduced Absorber Layer Thickness on Cu in Ga se2 Thin Film Solar Cells written by Vinodh Chandrasekaran and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The thickness of the Molybdenum back contact layer was increased to see if the amount of Sodium from the substrate had any effect on the device performance. The Ga/In ratio was altered and its effect was also studied. The 0.65um thick devices showed a large reduction in Voc̕s and Jsc̕s. The effect of Selenization time and Selenium flux during Selenization were studied at each of the different thicknesses.

Download or read book 2016 IEEE 43rd Photovoltaic Specialists Conference PVSC written by IEEE Staff and published by . This book was released on 2016-06-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: scientific and engineering technical conference covering all aspects of photovoltaics materials, devices, systems and reliability