{"title":"Back reflector texture and stability issues in high efficiency multijunction amorphous silicon alloy solar cells","authors":"A. Banerjee, K. Hoffman, X. Xu, J. Yang, S. Guha","doi":"10.1109/WCPEC.1994.520017","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520017","url":null,"abstract":"The role of the back reflector texture on the initial and stabilized efficiency of high efficiency triple-junction triple-bandgap amorphous silicon alloy based cells has been investigated. The devices have been deposited on Ag/ZnO back reflector possessing three different textures. The performance of the bottom single-junction a-SiGe alloy n-i-p cell on the three textures has also been analyzed. The value of the short-circuit current density of the n-i-p cell initially increases and then decreases with increasing texture. Light soaking results show that the higher textures exhibit superior device stability. Degradation as low as 8% has been obtained on the triple-junction cells.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73774880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gold interconnectors for solar generators in low Earth orbits","authors":"G. La Roche, C. Oxynos-Lauschke, K. Wehner","doi":"10.1109/WCPEC.1994.521659","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.521659","url":null,"abstract":"For low Earth orbit applications gold based electrical connections have keen developed consisting of 12.5 /spl mu/m thin gold solar cell interconnectors with stress relief loop, 50 /spl mu/m thick gold string terminations and gauge AWG 24 stranded gold wires. Modules with typical 4 cm by 6 cm silicon solar cells mounted on a lightweight carbon fibre reinforced honeycomb substrate were manufactured including the new components applied by resistance welding. A long duration thermal cycling test was started cycling two coupons at between -110/spl deg/C and +110/spl deg/C. As of November 1994, 27500 cycles have been completed, and the test is continuing. Evaluation of module integrity at periodic intervals yielded no measurable degradation up to date.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73804896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Wollweber, D. Schulz, W. Schroder, N. Abrosimov
{"title":"The growth of Si/sub x/Ge/sub 1-x/-crystals for infrared solar cell applications","authors":"J. Wollweber, D. Schulz, W. Schroder, N. Abrosimov","doi":"10.1109/WCPEC.1994.520202","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520202","url":null,"abstract":"Monocrystalline Si/sub x/Ge/sub 1-x/ alloys may be a powerful material for infrared solar cell applications. In comparison with pure Si, Ruiz et al. (1994) have shown that SiGe-solar cells should increase their efficiency by 2% for x=0.5. However the optimum is quite broad and the maximum of this benefit may be reached with low Ge content cells. On the other hand the availability of a large quantity of SiGe-bulk crystals through the whole composition range is suitable for studies of fundamental properties of SiGe alloys. The present work focuses on new results in the growth of SiGe-single crystals prepared by two methods: (i) an RF-heated float zone-technique; and (ii) a conventional Czochralski-technique.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73225619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"In situ characterization of growing hydrogenated amorphous silicon thin films by p-polarized laser light reflection measurement","authors":"N. Naito, M. Sumiya, M. Kawasaki, H. Koinuma","doi":"10.1109/WCPEC.1994.520023","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520023","url":null,"abstract":"In situ p-polarized laser light reflection measurement was applied to the determination of optical constants of growing a-Si:H thin films as well as to the detection of surface transient processes in plasma CVD. Turning off the plasma induced a slight but noticeable change in the reflectance. This reflectance change can be well explained by taking into account the surface relaxation process. When a 2 MHz supersonic vibration was applied to the substrate during the plasma CVD of a-Si:H, it was revealed that the refractive index and absorption coefficient of a-Si:H increased as compared with those deposited without the supersonic vibration. The result indicates that the supersonic vibration works to form a densified a-Si:H network, (presumably by improving the surface reaction).","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73582742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Hirasawa, K. Iida, S. Yamaguchi, N. Asayama, Y. Naito
{"title":"Design and drawing support system for photovoltaic array structure","authors":"T. Hirasawa, K. Iida, S. Yamaguchi, N. Asayama, Y. Naito","doi":"10.1109/WCPEC.1994.520160","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520160","url":null,"abstract":"This paper describes a design and drawing support system for a photovoltaic (PV) array structure. The operator inputs data (e.g. structure type, tilt angle, load conditions, etc.) into the system, which computes stress on each element of structure and outputs the calculated results. If the results are within the tolerance limit, a skeleton drawing of the structure is produced. The weight list of materials is also outputted on paper. When the results are beyond the limit, the data is modified by the operator and re-computed until the satisfactory results are shown.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75371667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Preparation and properties of high quality crystalline silicon films grown by ECR plasma deposition","authors":"S. DeBoer, V. Dalal","doi":"10.1109/WCPEC.1994.519958","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.519958","url":null,"abstract":"A process for growing high quality epitaxial silicon on heavily doped silicon (100) wafers at temperatures below 525/spl deg/C has been developed using a high vacuum electron cyclotron resonance (ECR) plasma deposition system. Plasma diagnostic work was done in order to optimize the growth conditions. The crystalline quality of our films has been verified using TEM, Raman and UV reflectance. Spreading resistance profiles (SRP) indicate that our undoped films are n-type with free carrier concentrations between 3/spl times/10/sup 16/ cm/sup -3/ and 3/spl times/10/sup 17/ cm/sup -3/. The junction between the heavily doped wafer and the undoped epi layer is shown to be abrupt. The mobilities of the carriers were measured using Hall measurements, and were found to be as high as in the best crystalline materials. This new technique may have significant applications for low cost Si solar cells.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75518672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael K. Bergman, J. Bigger, S. Hester, J. Serfass, J. Hoffner
{"title":"Implementation of the US utility industry's TEAM-UP commercialization initiative","authors":"Michael K. Bergman, J. Bigger, S. Hester, J. Serfass, J. Hoffner","doi":"10.1109/WCPEC.1994.521694","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.521694","url":null,"abstract":"TEAM-UP is a partnership program of the US electric utility industry and the US Department of Energy to help develop utility PV markets. TEAM-UP is a utility-directed program to significantly increase utility PV experience by promoting installations of utility PV power systems. Two primary program areas are proposed for TEAM-UP: (1) grid-independent applications (GIA)-an initiative to aggregate utility purchases of small-scale, grid-independent applications; and (2) grid-connected applications-an initiative to identify and competitively award cost-sharing contracts for grid-connected PV power systems with high market growth potential, or collective purchase programs involving multiple buyers. This paper describes these programs and outlines the schedule, the procurement status, and the results of surveys, public review workshops, and notices that are part of the TEAM-UP process.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75704701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Room-temperature FT-luminescence analysis of Cu(In,Ga)Se/sub 2/ films and devices","authors":"J. Webb, M. Contreras, R. Noufi","doi":"10.1109/WCPEC.1994.519861","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.519861","url":null,"abstract":"The authors report a rapid, convenient luminescence technique for quality control of polycrystalline Cu(In,Ga)Se/sub 2/ (CIGS) films and photovoltaic (PV) devices. The speed and convenience of the luminescence analyses were realized by using a Fourier transform (FT) Raman spectrophotometer which operates in the near-infrared (NIR) spectral region encompassing the band gap and defect levels of CIGS. With minor modifications to the FT-Raman spectrophotometer, the authors were able to detect both photoluminescence (PL) and electroluminescence (EL) from CIGS devices at room temperature. The FT-EL technique allows luminescence measurements to be made using this equipment at energies up to 1.3 eV, while the FT-PL technique is limited to energies below 1.15 eV. By increasing sensitivity and eliminating the need for sample cooling, this approach reduced the measurement time by an order of magnitude relative to comparable dispersive PL measurements. They used a fiberprobe accessory to the FT-Raman spectrophotometer to demonstrate that samples can be checked for uniformity at remote locations, e.g. online, using FT-PL spectroscopy. They also used a microscope accessory to obtain the PL spectra of visibly discolored regions some tens of microns in diameter on a CIGS device, and to show that these regions emit PL at significantly lower energy and intensity than nearby uniform regions of the device.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74210314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Technology challenges for space solar cells","authors":"P. Iles, F. Ho","doi":"10.1109/WCPEC.1994.520752","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520752","url":null,"abstract":"Current activity and trends in space cell technology are reviewed. A wider range of applications, and demand for higher efficiency cells have presented technical challenges. Rapid build-up in demand for commercial satellites has also posed challenges for the business planners. The technical challenges for space solar cells include the wider range of missions undertaken, and the demands for increased performance. Ways of coping with these technical challenges as well as the business challenges are discussed.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74244318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Evrard, T. Vermeulen, J. Poortmans, M. Caymax, P. Laermans, J. Nijs, R. Mertens
{"title":"The study of the influence of the layer resistivity of thin epitaxial Si cells","authors":"O. Evrard, T. Vermeulen, J. Poortmans, M. Caymax, P. Laermans, J. Nijs, R. Mertens","doi":"10.1109/WCPEC.1994.520514","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520514","url":null,"abstract":"Epitaxial layers on heavily doped CZ substrates were grown in an APCVD epitaxial system with different epitaxial layer resistivities: 0.2, 0.5, 1.0 and 2.5 ohm.cm, in order to investigate the influence of the resistivity on the solar cell characteristics. Textured and untextured layers were compared. I-V characteristics under normalised AM 1.5 illumination, dark I-V and spectral response were measured. The efficiencies and the photogenerated current were found to increase with increasing layer resistivities in the range of their investigations.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74331151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}