EPJ Photovoltaics最新文献

{"title":"Impact of PECVD μc-Si:H deposition on tunnel oxide for passivating contacts","authors":"A. Desthieux, J. Posada, P. Grand, C. Broussillou, B. Bazer-Bachi, G. Goaer, Davina Messou, M. Bouttemy, E. Drahi, P. Cabarrocas","doi":"10.1051/epjpv/2020001","DOIUrl":"https://doi.org/10.1051/epjpv/2020001","url":null,"abstract":"Passivating contacts are becoming a mainstream option in current photovoltaic industry due to their ability to provide an outstanding surface passivation along with a good conductivity for carrier collection. However, their integration usually requires long annealing steps which are not desirable in industry. In this work we study PECVD as a way to carry out all deposition steps: silicon oxide (SiOx), doped polycrystalline silicon (poly-Si) and silicon nitride (SiNx:H), followed by a single firing step. Blistering of the poly-Si layer has been avoided by depositing (p+) microcrystalline silicon (μc-Si:H). We report on the impact of this deposition step on the SiOx layer deposited by PECVD, and on the passivation properties by comparing PECVD and wet-chemical oxide in this hole-selective passivating contact stack. We have reached iVoc > 690 mV on p-type FZ wafers for wet-chemical SiOx(p+) μc-SiSiNx:H with no annealing step.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjpv/2020001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827582","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":"Optimized amorphous silicon nitride layers for the front side passivation of c-Si PERC solar cells","authors":"A. Okasha, B. Kafle, Benjamin Torda, Christopher Teßmann, M. Hofmann","doi":"10.1051/epjpv/2020003","DOIUrl":"https://doi.org/10.1051/epjpv/2020003","url":null,"abstract":"Plasma-enhanced chemical vapour deposition (PECVD) SiNx is the typical choice as anti-reflection coating (ARC) for Silicon based solar cells. However, there still exists a room for improvement in passivation quality of SiNx while maintaining good optics for the front side of a solar cell. In this paper, we studied in detail the optical and electrical properties of SiNx layers by varying the chamber pressure and substrate temperature in an industrially used inline PECVD tool. Both the optical as well as electrical properties of SiNx layers were found to be significantly influenced by the chamber pressure and substrate temperature. A trade-off between excellent optics and low surface recombination is observed with an increase in chamber pressure, whereas higher substrate temperature generally led to better passivation quality. The Si-H bond density, which is expected to directly influence the quality of surface passivation, increased at high pressure and at low substrate temperature. Based on our investigations, a good compromise between optics and surface passivation is struck to prepare optimized SiNx layers and apply them as passivation layers for the front side of passivated emitter and rear cell (PERC) solar cells. The best solar cells show high short-circuit current density (jSC) of 39.9 mA/cm2 corresponding to the SiNx layers with low parasitic absorption, good antireflection property, and excellent passivation of the surface and bulk silicon. The current-voltage (I-V) results are found to be in agreement with internal quantum efficiency (IQE) measurements of the solar cells.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"18 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjpv/2020003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827592","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":"How the absorber thickness influences the formation of reverse bias induced defects in CIGS solar cells","authors":"K. Bakker, Alix Rasia, Suzanne Assen, Basma Ben Said Aflouat, A. Weeber, M. Theelen","doi":"10.1051/epjpv/2020006","DOIUrl":"https://doi.org/10.1051/epjpv/2020006","url":null,"abstract":"When a PV module is partially shaded, the shaded solar cells operate in a reverse bias condition. For Cu(In,Ga)Se2 cells this condition can cause defects that irreversibly reduce the output of these cells and the full module. In order to design robust shade-tolerant CIGS modules details need to be known of the conditions at which these defects will be formed. In this study a large number of cells were exposed to different reverse bias conditions. By using simple statistics the probability of the occurrence of defects as a result of reverse bias at any given voltage has been determined. Based on our experiments we have found that the absorber thickness is one of the main parameters that affects the shade-tolerance: the thicker the absorber, the more shade tolerant the CIGS module will be.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"36 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827639","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":"Elaboration of wide bandgap CIGS on silicon by electrodeposition of stacked metal precursors and sulfur annealing for tandem solar cell applications","authors":"A. Crossay, D. Cammilleri, A. Thomere, Bienlo Zerbo, Amelle Rebai, N. Barreau, D. Lincot","doi":"10.1051/EPJPV/2020008","DOIUrl":"https://doi.org/10.1051/EPJPV/2020008","url":null,"abstract":"A method was developed for the electrodeposition of Cu-In-Ga precursor layers to elaborate Cu(In,Ga)(S,Se)2 (CIGS) thin films on silicon substrates for future application as silicon/wide-gap CIGS tandem solar cells. An underlayer of Ag was first deposited on silicon substrates to ensure a good adhesion of the electrodeposited stack and to serve as cathode during the deposition process. Cu, In and Ga layers were then sequentially electrodeposited. Ag-Cu-In-Ga precursor layers were finally subjected to elemental sulfur annealing at 600 °C. Formation of compact and adherent AgCIGS is observed. X ray diffraction and photoluminescence analyses confirm the formation of wide-gap CIGS of about 1.6 eV, with a spontaneous gallium grading over the depth of the sample leading to the formation of a bi-layer structure with a gallium rich layer at the interface with silicon.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827659","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":"Rear surface passivation of ultra-thin CIGS solar cells using atomic layer deposited HfOx","authors":"G. Birant, Jorge Mafalda, Romain Scaffidi, J. Wild, D. Buldu, T. Kohl, G. Brammertz, M. Meuris, J. Poortmans, B. Vermang","doi":"10.1051/epjpv/2020007","DOIUrl":"https://doi.org/10.1051/epjpv/2020007","url":null,"abstract":"In this work, hafnium oxide layer is investigated as rear surface passivation layer for ultra-thin (550 nm) CIGS solar cells. Point contact openings in the passivation layer are realized by spin-coating potassium fluoride prior to absorber layer growth. Contacts are formed during absorber layer growth and visualized with scanning electron microscopy (SEM). To assess the passivating qualities, HfOx was applied in a metal-insulator-semiconductor (MIS) structure, and it demonstrates a low interface trap density in combination with a negative density of charges. Since we used ultra-thin devices that are ideal to probe improvements at the rear, solar cell results indicated improvements in all cell parameters by the addition of 2 nm thick HfOx passivation layer with contact openings.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjpv/2020007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827649","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":"The effect of the recombination mechanisms location on the temperature sensitivity of thin-film photovoltaic cells","authors":"N. Kata, D. Diouf, A. Darga, A. Maiga","doi":"10.1051/epjpv/2019008","DOIUrl":"https://doi.org/10.1051/epjpv/2019008","url":null,"abstract":"Thin film solar cells temperature sensitivity and impact of the main recombination mechanism location are investigated in this paper. The main mechanisms in bulk and at the heterojunction interface are discriminated. Using a 1D simulation software, “Solar Cell Capacitance Simulator” (SCAPS), we observed a higher temperature coefficient of open circuit voltage (Voc) for cells with main recombination centers at the interface than the one with main recombination centers in volume. Furthermore, an LTSpice module model is used to visualize the effects of the recombination centers' location on the performance ratios of the modules. The results show more degradation for the ratios performance of cells with the main recombination mechanisms at the interface than those in volume.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjpv/2019008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47073091","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":"The use of liquid-phase method from DMSO solutions for synthesis of CZTS thin film materials","authors":"V. Rakitin, Pavel E. Varushkin, H. Xin, G. F. Novikov","doi":"10.1051/EPJPV/2019007","DOIUrl":"https://doi.org/10.1051/EPJPV/2019007","url":null,"abstract":"The possibility of synthesis of CZTS thin films on glass substrates from DMSO precursor solutions containing various quantity of copper ions was investigated. The dependence of composition of final CZTS compounds obtained from precursor solutions with different copper ion concentration in DMSO was shown. It was obtained that with the introduction of a low additive of copper ion concentration one can synthesize CZTS thin films with kesterite structure as well as with secondary phases (tin sulfides of SnS, Sn2S3). The increase of the concentration of copper ions in DMSO precursor solution promotes the formation of CZTS thin films with kesterite phase and the minimum content of impurities.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJPV/2019007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42879451","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":"Solar investment risk mitigation − are we all on the same page?","authors":"T. Sauer","doi":"10.1051/epjpv/2019005","DOIUrl":"https://doi.org/10.1051/epjpv/2019005","url":null,"abstract":"Currently, the PV solar sector represents approx. 2% of worldwide annual electricity production (https://webstore.iea.org/world-energy-outlook-2018), and therefore, is just at the verge of becoming visible in most countries. As the PV sector becomes increasingly visible to the next order of magnitude sometime in future, representing 20% in the electricity mix and beyond, it is now a good time to discuss reliability, predictability, and performance of PV power plants and as a consequence, the improvement potential for financial returns. Building on this train of thought, this article will provide a short introduction of PV power plant risks, predominantly related to technical performance. The question of risk mitigation measures will then be discussed: On the one side, quality assurance is a viable risk mitigation measure. However, even with quality assurance measures implemented, there are limitations when it comes to backstopping financial losses in the event that the performance deteriorates more than predicted and warranted by the manufacturers, or if the manufacturers or EPC's are no longer in business when incidental power degrades beyond calculated limits. Insurance solutions seem to provide an additional risk mitigation measure. Most insurance solutions on the market, however, only cover against externally induced risk exposures, e.g. severe weather, theft. Most of these insurance solutions follow a certain minimum standard. A few insurance products offer performance insurances where general cover is less standardized. All this triggers the question of how to look at insurance solutions. The interests of an insurance company are generally different than those of the insured stakeholders. These different viewpoints will be discussed, and selected warranty and insurance aspects will be considered. Recently, approximately 3500 insurance claim cases were statistically analyzed (http://www.pvstatlab.rwth-aachen.de/index.php/PVScan-project.html). Selected results of this analysis will be discussed. The article closes with an outlook of how insurers can likewise mitigate their risk exposure − in the end, insurers are only as good as the balance of the solvency resulting from their business model, or in the terminology of the insurance sector, the loss ratio must be at an acceptable level. This is where IECRE, the IEC System for Certification to Standards Relating to Equipment for Use in Renewable Energy Applications (https://www.iecre.org/), offering an international standard for certification − and in future − a rating system for PV power plants on a system level comes into play.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/epjpv/2019005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43503010","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":"Detailed balance calculations for hot-carrier solar cells: coupling high absorptivity with low thermalization through light trapping","authors":"Maxime Giteau, D. Suchet, S. Collin, J. Guillemoles, Y. Okada","doi":"10.1051/EPJPV/2019001","DOIUrl":"https://doi.org/10.1051/EPJPV/2019001","url":null,"abstract":"Hot-carrier solar cells could enable an efficiency gain compared to conventional cells, provided that a high current can be achieved, together with a hot-carrier population. Because the thermalization rate is proportional to the volume of the absorber, a fundamental requirement is to maximize the density of carriers generated per volume unit. In this work, we focus on the crucial role of light trapping to meet this objective. Using a detailed balance model taking into account losses through a thermalization factor, we obtained parameters of the hot-carrier population generated under continuous illumination. Different absorptions corresponding to different light path enhancements were compared. Results are presented for open-circuit voltage, at maximum power point and as a function of the applied voltage. The relation between the parameters of the cell (thermalization rate and absorptivity) and its characteristics (temperature, chemical potential, and efficiency) is explained. In particular, we clarify the link between absorbed light intensity and chemical potential. Overall, the results give quantitative values for the thermalization coefficient to be achieved and show that in the hot-carrier regime, absorptivity enhancement leads to an important increase in the carrier temperature and efficiency.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJPV/2019001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827445","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":"KPFM surface photovoltage measurement and numerical simulation","authors":"C. Marchat, J. P. Connolly, J. Kleider, J. Alvarez, L. J. Koduvelikulathu, Jean-Baptiste Puel","doi":"10.1051/EPJPV/2019002","DOIUrl":"https://doi.org/10.1051/EPJPV/2019002","url":null,"abstract":"A method for the analysis of Kelvin probe force microscopy (KPFM) characterization of semiconductor devices is presented. It enables evaluation of the influence of defective surface layers. The model is validated by analysing experimental KPFM measurements on crystalline silicon samples of contact potential difference (VCPD) in the dark and under illumination, and hence the surface photovoltage (SPV). It is shown that the model phenomenologically explains the observed KPFM measurements. It reproduces the magnitude of SPV characterization as a function of incident light power in terms of a defect density assuming Gaussian defect distribution in the semiconductor bandgap. This allows an estimation of defect densities in surface layers of semiconductors and therefore increased exploitation of KPFM data.","PeriodicalId":42768,"journal":{"name":"EPJ Photovoltaics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/EPJPV/2019002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57827459","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}