{"title":"A study of thermal, voltage, and photoinduced effects on the external quantum efficiency of CuInGaSe2 (CIGS) photovoltaic devices","authors":"R. Feist, M. Mills, R. K. Thompson, N. Ramesh","doi":"10.1109/PVSC.2012.6317832","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317832","url":null,"abstract":"The purpose of this study was to assess the performance of CuInGaSe2 (CIGS) solar cells ranging from 6.9-11.2% efficiency to identify means of improving device performance. One of the main drivers for this work was to take an independent look at elevated operating temperatures associated with BIPV products like Dow's POWERHOUSE™ shingle system for performance differences as a function of system operating temperature independent of increasing efficiency to help future product definition. For three of the four samples we observed a clear lack of dark-light current-voltage (JV) superposition and correspondingly via external quantum efficiency (EQE) measurements an electrical field dependent carrier collection response in the blue regime. By inference this performance indicates the presence of impurities in the device, likely in the CdS film that could present an opportunity to further improve the CIGS device performance.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"70 1","pages":"001266-001270"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74772719","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. Tanaka, T. Mochinaga, K. Saito, Q. Guo, M. Nishio, K. Yu, W. Walukiewicz
{"title":"Synthesis and optical properties of ZnTe1−xOx highly mismatched alloys for intermediate band solar cells","authors":"T. Tanaka, T. Mochinaga, K. Saito, Q. Guo, M. Nishio, K. Yu, W. Walukiewicz","doi":"10.1109/PVSC.2012.6317579","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317579","url":null,"abstract":"Highly mismatched ZnTe1-xOx (ZnTeO) alloys have been grown by molecular beam epitaxy. X-ray diffraction (XRD) analyses showed that a single-phase ZnTeO layer were grown with a substitutional O composition x up to 1.34% on ZnTe(001) substrate in this experiments. Optical transitions associated with the lower (E-) and upper (E+) conduction subbands resulting from the anticrossing interaction between the localized O states and the extended conduction states of ZnTe were clearly observed, and the dependence of the energy position of these bands on the O composition was consistent with the band anticrossing model. The photovoltaic activities of solar cells using ZnTeO layers are also reported.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"83 1","pages":"000109-000112"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76129026","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}
K. Komoto, E. Cunow, C. Breyer, D. Faiman, K. Megherbi, P. van der Vleuten
{"title":"IEA PVPS Task8: Study on Very Large Scale Photovoltaic (VLS-PV) Systems","authors":"K. Komoto, E. Cunow, C. Breyer, D. Faiman, K. Megherbi, P. van der Vleuten","doi":"10.1109/PVSC.2012.6317938","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317938","url":null,"abstract":"The purpose of IEA PVPS Task8, Study on Very Large Scale Photovoltaic (VLS-PV) Systems, is to examine and evaluate the potential and feasibility of VLS-PV systems, which have capacities ranging from several megawatts to gigawatts, and to develop strategies for implementation of the VLS-PV systems in the future. Our study has comprehensively analyzed the major issues involved in such large scale applications, based on the latest scientific and technological developments and by means of close international co-operation with experts from different countries. Solar power plants in desert regions increasingly count as a realistic energy option. Very Large Scale solar power plants start to appear around the world. In order to accelerate the current transition towards renewable energy, development of VLS-PV power generation systems that can be deployed on a massive scale is one of the ways for this transformation. This paper will present an overview of relevant issues and the potential of VLS-PV, guidelines for VLS-PV systems, and technical as well as strategic options for implementing VLS-PV.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"35 1","pages":"001778-001782"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75084254","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}
S. Thibert, D. Chaussy, D. Beneventi, N. Reverdy-Bruas, J. Jourdan, B. Bechevet, S. Mialon
{"title":"Silver ink experiments for silicon solar cell metallization by flexographic process","authors":"S. Thibert, D. Chaussy, D. Beneventi, N. Reverdy-Bruas, J. Jourdan, B. Bechevet, S. Mialon","doi":"10.1109/PVSC.2012.6318049","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318049","url":null,"abstract":"The metallization of silicon solar cells becomes more and more critical due to the recent soaring prices of silver. Flexographic printing can be used to deposit the seed layer in a “seed and plate” scheme to replace screen printing, classically employed in production lines but limited by its resolution. To develop the process, several inks prepared from standard screen printing paste were tested. First, different rheological experiments were performed. Then the different inks were printed on silicon solar cells and a correlation was pointed out between rheological properties and printing results. The present work demonstrates that flexography is a potential candidate to deposit silver seed layer with a width as low as 30 μm with a printing speed of 0.5 m/s. Moreover the importance of rheological experiments during a printing process development is underlined.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"72 1","pages":"002266-002270"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74952119","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}
B. Newton, Abu H. Safe, M. Benemara, S. Yu, H. Naseem
{"title":"Fabrication of site specific amorphous/nanocrystalline silicon composite thin film for solar cells","authors":"B. Newton, Abu H. Safe, M. Benemara, S. Yu, H. Naseem","doi":"10.1109/PVSC.2012.6317822","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317822","url":null,"abstract":"The absorption properties of amorphous silicon (α-Si) and the electron transport properties of nanocrystalline silicon are combined in a novel composite material for thin film silicon solar cells. In this work a composite film composed of α-Si with site specific areas of nanocrystalline material was created. Al was deposited through a SiO2 template containing nanometer sized apertures with an approximate diameter of 250 nm onto an α-Si film supported by a <;100>; crystalline silicon substrate. It was then annealed at 350°C. The annealing caused crystallization only at sites where the Al was in contact with the α-Si surface. The AIC created site specific three dimensional nanocrystalline structures embedded in a thin film of α-Si. After grain boundary passivation these nanocrystalline sites will provide pathways for charge carriers that are less defect dense than the α-Si film. TEM samples were fabricated from the composite film utilizing the focus ion beam. The growth characteristics of these 3D nanostructures and the α-Si thin film were characterized utilizing ESEM and the TEM.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"89 1","pages":"001220-001224"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74964083","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}
S. Noguchi, S. Yagi, Y. Hijikata, K. Onabe, S. Kuboya, H. Yaguchi
{"title":"Analysis of the energy structure of nitrogen δ-doped GaAs superlattices for high efficiency intermediate band solar cells","authors":"S. Noguchi, S. Yagi, Y. Hijikata, K. Onabe, S. Kuboya, H. Yaguchi","doi":"10.1109/PVSC.2012.6317573","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317573","url":null,"abstract":"Nitrogen δ-doped GaAs superlattices were fabricated and their energy structures were investigated. Several transitions related to E+ band of nitrogen δ-doped regions were observed in photoreflectance (PR) spectra at energies ranging 1.5-1.7 eV for the superlattices at which no transitions were observed for uniformly doped GaAsN. The PR signal intensity of E+ related band transitions is significantly higher than those observed in uniformly doped GaAsN. This enhancement of E+ related band transitions is advantageous as an intermediate band material, and thus, nitrogen δ-doped GaAs superlattice structures are expected to be an excellent alternative for the use of intermediate band solar cells.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"1 1","pages":"000083-000086"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76503057","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}
Zhenjiao Wang, P. Han, Qinglei Meng, H. Qian, Jiaqi Wu, Yongfei Jiang, N. Tang, Hongyan Lu, Haidong Zhu, Rulong Chen, P. Yang, J. Ji, Zhengrong Shi, A. Sugianto, S. Wenhem
{"title":"20.3% efficiency rear passivated silicon solar cells with local back contact using commercial P-Cz wafers","authors":"Zhenjiao Wang, P. Han, Qinglei Meng, H. Qian, Jiaqi Wu, Yongfei Jiang, N. Tang, Hongyan Lu, Haidong Zhu, Rulong Chen, P. Yang, J. Ji, Zhengrong Shi, A. Sugianto, S. Wenhem","doi":"10.1109/PVSC.2012.6317806","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317806","url":null,"abstract":"In this paper, progress results on the next generation Pluto technology were reported. In the next generation Pluto, we focused on the rear surface design, by improvement of the back internal reflection and passivation we got 20.3% cell efficiency with very high Jsc. Still there is further improvement of the cell design to get high FF and Eff.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"18 1","pages":"001154-001157"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80033030","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":"System performance analysis and estimation of degradation rates based on 500 years of monitoring data","authors":"N. Reich, A. Goebel, D. Dirnberger, K. Kiefer","doi":"10.1109/PVSC.2012.6317890","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317890","url":null,"abstract":"Fraunhofer ISE has been involved in monitoring of PV systems since the “1000-roofs-program” in the 1990s. In a few of these “old systems” equipment is still in place, metering PV electricity output and plane-of-array irradiation. The majority of ~300 PV power plants in our monitoring campaign today, however, is large-scale and built in the past 10 years. In this paper, we briefly review the historical development of the Performance Ratio (PR) and how average PR for newly built systems increased to almost 90%. This rather high PR of 90% only holds, however, if calculated by on-site irradiation acquired with c-Si reference cells and for climates comparable with those in Germany. Next, we use about 500 years of monitoring data on aggregate to perform an analysis of variations of the PR over time. To this end, data points at similar environmental conditions are extracted from long-term time series as to calculate so-called “rates-of-change” of the PR. Highly scattered “rates-of-change” are obtained, however, not allowing for the estimation of specific degradation rates on the system level yet. To this end, we finally revisit uncertainties of irradiance sensors and in particular revisit our irradiance sensor re-calibration data.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"66 1","pages":"001551-001555"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80215542","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":"Design of metamorphic dual-junction InGaP/GaAs solar cell on Si with efficiency greater than 29% using finite element analysis","authors":"N. Jain, M. Hudait","doi":"10.1109/PVSC.2012.6318003","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318003","url":null,"abstract":"Heterogeneous integration of multijunction III-V solar cells on Si is a promising solution for the widespread commercialization of III-V cells. However, the polar on non-polar epitaxy and 4% lattice-mismatch between GaAs and Si results in formation of defects and dislocations, which can significantly impede the minority carrier lifetime and hence the cell performance. We have investigated the impact of threading dislocation density on the performance of dual-junction (2J) n+/p InGaP/GaAs solar cells on Si. Using our calibrated model, the metamorphic 2J cell on Si was optimized by tailoring the 2J cell design on Si to achieve current-matching between the subcells at a realistic threading dislocation density of 106 cm-2. We present a novel 2J InGaP/GaAs cell design on Si at a threading dislocation density of 106 cm-2 which exhibited a theoretical conversion efficiency of greater than 29% at AM1.5G spectrum, indicating a path for viable III-V multijunction cell technology on Si.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"47 1","pages":"002056-002060"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79076041","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}
S. Athreya, R. Sharma, K. Kauffmann, L. López, Jie Feng
{"title":"Simulation guided design of flexible photovoltaic laminates","authors":"S. Athreya, R. Sharma, K. Kauffmann, L. López, Jie Feng","doi":"10.1109/PVSC.2012.6317978","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317978","url":null,"abstract":"Photovoltaic (PV) modules are manufactured using various PV cell technologies. The packaging requirements vary for each of the PV technologies and depend on their inherent thermo-mechanical properties and environmental stability of the cell. Thin film PV has the relative advantage of flexibility vis-à-vis their rigid and brittle competitors. This paper discusses the use of Finite Element Analysis (FEA) to develop a framework for guiding the design of flexible Building Integrated Photovoltaic (BIPV) shingles utilizing thin film PV cells. Microglass (0.2-0.3 mm thick glass) was chosen as the top barrier layer to exploit the flexibility of the thin film PV material. However, microglass alone does not provide sufficient protection to the shingle to meet regulatory impact resistance requirements. This paper discusses the use of FEA to guide the selection of reinforcing polymer layers and their placement around the microglass to enable microglass-based flexible laminates to sustain hail impact. FEA was used to guide the selection of reinforcing polymers and their placement in the laminate structure. Hail impact was modeled as static indentation and stresses were calculated in all layers of the laminate. This model was used to compare around 50 laminates generated through systematic variation of the polymer mechanical properties and laminate designs. Based on the analysis of the stresses generated in the microglass and other layers in these laminates, it is found that the optimal laminate design would consist of an elastomeric reinforcing layer above the microglass and a rigid polymer layer below it. An additional layer of a rigid polymer above the elastomeric layer can further reduce stresses in the laminate; however, relatively large thickness of this layer might be needed to get any significant stress reduction. The ideal location for the rigid reinforcing layer has been identified to be between the cell and the bottom barrier layer. The model predictions have been partially validated through hail impact testing.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":"14 1","pages":"001952-001957"},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79142310","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}