Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186049
P. Yang, I. Chan, C. H. Lin, Y. L. Chang
The effect of low irradiance for thin film solar cells is investigated in this work. First, a-Si:H/CIGS/DSSC/OPV four kinds of thin film solar cells are fabricated and measured with the sun simulator (AM 1.5G, 100 mW/cm2). Then, the saturation current density J0 is extracted from the Voc and Jsc. Spectral irradiance of the desk light, LED light, sun light at the windowsill and fluorescent lamp are used to calculate the electrical parameters of the solar cells in indoor lighting conditions. From the calculation, a-Si solar cell under the LED light achieves the highest cell efficiency of 17.68%. In real measurement, it is also demonstrated that the cell efficiency of a-Si solar cell can reach 15.2% under the irradiance of 1.1 mW/cm2 LED light.
{"title":"Thin film solar cells for indoor use","authors":"P. Yang, I. Chan, C. H. Lin, Y. L. Chang","doi":"10.1109/PVSC.2011.6186049","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186049","url":null,"abstract":"The effect of low irradiance for thin film solar cells is investigated in this work. First, a-Si:H/CIGS/DSSC/OPV four kinds of thin film solar cells are fabricated and measured with the sun simulator (AM 1.5G, 100 mW/cm2). Then, the saturation current density J0 is extracted from the Voc and Jsc. Spectral irradiance of the desk light, LED light, sun light at the windowsill and fluorescent lamp are used to calculate the electrical parameters of the solar cells in indoor lighting conditions. From the calculation, a-Si solar cell under the LED light achieves the highest cell efficiency of 17.68%. In real measurement, it is also demonstrated that the cell efficiency of a-Si solar cell can reach 15.2% under the irradiance of 1.1 mW/cm2 LED light.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121506251","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186387
Yen-Chih Liu, Wei-Yu Chen, Chien-Hung Lin, Chi-Chun Li
Selective emitter in crystalline silicon solar cells improves the cell efficiency by reducing the recombination in the emitter region while maintaining low contact resistance to the front side electrodes. There are many approaches to realize selective emitter solar cells, some more complicated than the others, but all involve creating heavier doping in the region under electrodes. In this paper, we present the effect of selective emitter patterns, with or without heavy doping under busbars, on the solar cell performance. The results showed basically identical electrical characteristics for both types of patterns. Even though the selective emitter structure in this study was made with a printable dopant approach, the same results could apply to other selective emitter methods, including laser doping and ion implantation. This conclusion points to potentially significant savings in materials and/or processing time as heavy doping is needed only to cover the finger area but not the busbars.
{"title":"Crystalline silicon solar cells selective emitter pattern design","authors":"Yen-Chih Liu, Wei-Yu Chen, Chien-Hung Lin, Chi-Chun Li","doi":"10.1109/PVSC.2011.6186387","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186387","url":null,"abstract":"Selective emitter in crystalline silicon solar cells improves the cell efficiency by reducing the recombination in the emitter region while maintaining low contact resistance to the front side electrodes. There are many approaches to realize selective emitter solar cells, some more complicated than the others, but all involve creating heavier doping in the region under electrodes. In this paper, we present the effect of selective emitter patterns, with or without heavy doping under busbars, on the solar cell performance. The results showed basically identical electrical characteristics for both types of patterns. Even though the selective emitter structure in this study was made with a printable dopant approach, the same results could apply to other selective emitter methods, including laser doping and ion implantation. This conclusion points to potentially significant savings in materials and/or processing time as heavy doping is needed only to cover the finger area but not the busbars.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121561619","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186540
Wei-Lun Chang, En-Ting Liu, Chia‐Hua Chang, P. Yu, Chien-Hung Wu
Thin wafer-based solar cells have the potential to significantly decrease the cost of photovoltaics. Light trapping is particularly critical in such thin-wafer crystalline silicon solar cells in order to increase light absorption and hence cell efficiency. In this article we investigate the indium-tin-oxide nanowhisker on textured silicon surface for enhancing the near-infrared absorbance of silicon photovoltaics. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves quantum efficiencies enhancement for a broad wavelength range of 900 to 1100 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.
{"title":"Efficiency enhancement of the thin-silicon photovoltaics using indium-tin-oxide nanowhiskers","authors":"Wei-Lun Chang, En-Ting Liu, Chia‐Hua Chang, P. Yu, Chien-Hung Wu","doi":"10.1109/PVSC.2011.6186540","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186540","url":null,"abstract":"Thin wafer-based solar cells have the potential to significantly decrease the cost of photovoltaics. Light trapping is particularly critical in such thin-wafer crystalline silicon solar cells in order to increase light absorption and hence cell efficiency. In this article we investigate the indium-tin-oxide nanowhisker on textured silicon surface for enhancing the near-infrared absorbance of silicon photovoltaics. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves quantum efficiencies enhancement for a broad wavelength range of 900 to 1100 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"453 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121616800","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186066
J. van Deelen, H. Rendering, Hero het Mannetje, A. Hovestad
Various transparent conducting materials are compared based on their transparency versus sheet resistance characteristics. At present, transparent conducting oxides (TCOs) are still superior in performance compared to various recent alternatives and can only be surpassed by the combination of TCOs with a metal grid. Results on modeling and design optimization are presented using a monolithically integrated CIGS cell configuration as case. This study showed that considerable efficiency enhancement (17% in power output) can be achieved for metal grid TCO combinations compared to single TCOs. Conductivity improvement has been experimentally verified on both commercial ITO PET foil as well as on ZnO coated glass with electrochemically deposited metal grids. Conductivities below 0,1 Ohm/sq were reached and 80 times and 400 times conductivity improvements were obtained at a transparency loss of only 3% and 6%, respectively. It was also found that electrochemical deposition results in more conductive and more transparent grids than obtained by Ag-ink screen printing.
{"title":"Grids on TCOs for higly transparent materials with a resistivity below 1 Ohm/sq","authors":"J. van Deelen, H. Rendering, Hero het Mannetje, A. Hovestad","doi":"10.1109/PVSC.2011.6186066","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186066","url":null,"abstract":"Various transparent conducting materials are compared based on their transparency versus sheet resistance characteristics. At present, transparent conducting oxides (TCOs) are still superior in performance compared to various recent alternatives and can only be surpassed by the combination of TCOs with a metal grid. Results on modeling and design optimization are presented using a monolithically integrated CIGS cell configuration as case. This study showed that considerable efficiency enhancement (17% in power output) can be achieved for metal grid TCO combinations compared to single TCOs. Conductivity improvement has been experimentally verified on both commercial ITO PET foil as well as on ZnO coated glass with electrochemically deposited metal grids. Conductivities below 0,1 Ohm/sq were reached and 80 times and 400 times conductivity improvements were obtained at a transparency loss of only 3% and 6%, respectively. It was also found that electrochemical deposition results in more conductive and more transparent grids than obtained by Ag-ink screen printing.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121626829","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186553
H. Muthurajan, D. Lai, C. Tan
We have developed a novel software package which is able to simulate the performance parameters of the solar cells based on diffusion process parameters as well as finger-bus design parameters. An algorithm for computer aided design (CAD) incorporated in this software package is useful for designing and optimizing the finger-bus dimension for optimum solar energy harvesting. The CAD algorithm of this software package can save the optimized finger-bus design in a .dxf format which can then be directly used as layout for mask making of the metallization layers using screen printing, CMOS based lithography or e-beam writer. The .dxf format file generated by our software package can also be viewed using other CAD softwares such as AutoCAD, L-Edit, etc. This software package also simulate the sheet resistivity of the doped poly-silicon layer based on the process parameters — POCl3 diffusion temperature, duration of POCl3 diffusion reaction, annealing temperature and annealing duration. This research paper presents the new algorithm incorporated in the novel software as discussed above as well as the optimization of the process parameters and finger-bus design.
{"title":"Simulation and computer aided design of silicon solar cells for process and performance parameters optimization","authors":"H. Muthurajan, D. Lai, C. Tan","doi":"10.1109/PVSC.2011.6186553","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186553","url":null,"abstract":"We have developed a novel software package which is able to simulate the performance parameters of the solar cells based on diffusion process parameters as well as finger-bus design parameters. An algorithm for computer aided design (CAD) incorporated in this software package is useful for designing and optimizing the finger-bus dimension for optimum solar energy harvesting. The CAD algorithm of this software package can save the optimized finger-bus design in a .dxf format which can then be directly used as layout for mask making of the metallization layers using screen printing, CMOS based lithography or e-beam writer. The .dxf format file generated by our software package can also be viewed using other CAD softwares such as AutoCAD, L-Edit, etc. This software package also simulate the sheet resistivity of the doped poly-silicon layer based on the process parameters — POCl3 diffusion temperature, duration of POCl3 diffusion reaction, annealing temperature and annealing duration. This research paper presents the new algorithm incorporated in the novel software as discussed above as well as the optimization of the process parameters and finger-bus design.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126449756","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186359
S. Goodnick, C. Honsberg
Third generation concepts in photovoltaic devices depend critically on the dynamics of ultrafast carrier relaxation and electron-phonon interactions on very short times scales in nanostructures such as quantum wells, wires and dots. Hot carrier solar cells in particular depend on the reduction in the energy relaxation rate in an absorber material, where hot carriers are extracted through energy selective contacts. Here we investigate the short time carrier relaxation in quantum well, hot electron solar cells under varying photoexcitation conditions using ensemble Monte Carlo (EMC) simulation coupled with rate equation models, to understand the limiting factors affecting cell performance. In particular, we focus on the potential role of hot phonons in reducing the energy loss rate in order to achieve sufficient carrier temperature for efficient performance.
{"title":"Ultrafast carrier relaxation and nonequilibrium phonons in hot carrier solar cells","authors":"S. Goodnick, C. Honsberg","doi":"10.1109/PVSC.2011.6186359","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186359","url":null,"abstract":"Third generation concepts in photovoltaic devices depend critically on the dynamics of ultrafast carrier relaxation and electron-phonon interactions on very short times scales in nanostructures such as quantum wells, wires and dots. Hot carrier solar cells in particular depend on the reduction in the energy relaxation rate in an absorber material, where hot carriers are extracted through energy selective contacts. Here we investigate the short time carrier relaxation in quantum well, hot electron solar cells under varying photoexcitation conditions using ensemble Monte Carlo (EMC) simulation coupled with rate equation models, to understand the limiting factors affecting cell performance. In particular, we focus on the potential role of hot phonons in reducing the energy loss rate in order to achieve sufficient carrier temperature for efficient performance.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126538518","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186477
E. Demirok, P. C. González, Martin C. Svendsen, Kenn H. B. Frederiksen, D. Sera, R. Teodorescu
The main objective of this study is to increase penetration level of photovoltaic (PV) power production in the grid by considering line overvoltage and transformer overloading limitations. The study presents a reactive power control method based on sensitivity analysis for grid-connected distributed solar inverters. The sensitivity analysis shows that reactive power support is more effective on the grid voltage regulation if the solar inverter is located at the end of the feeder. Therefore, higher power factor (PF) should be set for the inverter which is connected closer to substation due to smaller impedance observed from connection point to upstream network. Based on this knowledge, location-dependent PF set values are assigned to each solar inverter. In order to prevent unnecessary reactive power absorption from the grid, active power variation is also measured and considered in the control method. Compared to the equally fixed PF dispatching among inverters, the proposed method provides smaller network losses and MV/LV transformer loading that allows more PV system installations. Performance comparison of different reactive control methods is achieved by simulation of a real test network. Additionally, experimental reactive power control setup has been built together with a solar simulator and a single-stage 2-level inverter. The setup verifies that the control method can be easily integrated into inverters.
{"title":"A reactive power control strategy for distributed solar inverters in low voltage rural distribution grids without communication infrastructure","authors":"E. Demirok, P. C. González, Martin C. Svendsen, Kenn H. B. Frederiksen, D. Sera, R. Teodorescu","doi":"10.1109/PVSC.2011.6186477","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186477","url":null,"abstract":"The main objective of this study is to increase penetration level of photovoltaic (PV) power production in the grid by considering line overvoltage and transformer overloading limitations. The study presents a reactive power control method based on sensitivity analysis for grid-connected distributed solar inverters. The sensitivity analysis shows that reactive power support is more effective on the grid voltage regulation if the solar inverter is located at the end of the feeder. Therefore, higher power factor (PF) should be set for the inverter which is connected closer to substation due to smaller impedance observed from connection point to upstream network. Based on this knowledge, location-dependent PF set values are assigned to each solar inverter. In order to prevent unnecessary reactive power absorption from the grid, active power variation is also measured and considered in the control method. Compared to the equally fixed PF dispatching among inverters, the proposed method provides smaller network losses and MV/LV transformer loading that allows more PV system installations. Performance comparison of different reactive control methods is achieved by simulation of a real test network. Additionally, experimental reactive power control setup has been built together with a solar simulator and a single-stage 2-level inverter. The setup verifies that the control method can be easily integrated into inverters.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128033047","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186167
Rocco A. Panella, B. Ydstie, D. Prieve
Using electrokinetics and fluid mechanics, we are designing a method to rapidly deposit titania nanoparticles onto transparent conductive oxide surfaces for use in dye solar cell anodes. Manipulating the pH and ionic strength of an aqueous solution makes it possible to control the surface potential of submerged oxide surfaces such as titania and tin oxide. By using pH values near and below 5.5, it is possible to create conditions where titania nanoparticles are stable and electrostatically repel each other in a dilute, aqueous suspension, but are attracted to various tin oxide surfaces. We can then use fluid flow such as that from a rotating disk or impinging jet to deliver nanoparticles adequately close to the surface such that they adhere via strong van der waals forces. For particles which are made in solution via oxidation, this technique offers the major advantage of never drying the particles, thus allowing them to remain un-aggregated until they deposit onto the surface. We have shown that we can monitor particle deposition in situ by measuring the zeta potential of a surface using a rotating disk electrode apparatus. The measured difference in iso-electric point of titania and both fluorine- and indium-tin oxide shown in this work indicates that we should have some control over the rate and extent of particle deposition. Currently, we have deposited titania nanoparticle layers which are several layers thick and consist of particles with diameters smaller than 10 nm; these tightly packed layers have applications as blocking layers to prevent unwanted shunts in dye solar cells.
{"title":"Rapid deposition of titania nanoparticles on tin oxide for dye solar cell anodes using fluid mechanics and eletrokinetics","authors":"Rocco A. Panella, B. Ydstie, D. Prieve","doi":"10.1109/PVSC.2011.6186167","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186167","url":null,"abstract":"Using electrokinetics and fluid mechanics, we are designing a method to rapidly deposit titania nanoparticles onto transparent conductive oxide surfaces for use in dye solar cell anodes. Manipulating the pH and ionic strength of an aqueous solution makes it possible to control the surface potential of submerged oxide surfaces such as titania and tin oxide. By using pH values near and below 5.5, it is possible to create conditions where titania nanoparticles are stable and electrostatically repel each other in a dilute, aqueous suspension, but are attracted to various tin oxide surfaces. We can then use fluid flow such as that from a rotating disk or impinging jet to deliver nanoparticles adequately close to the surface such that they adhere via strong van der waals forces. For particles which are made in solution via oxidation, this technique offers the major advantage of never drying the particles, thus allowing them to remain un-aggregated until they deposit onto the surface. We have shown that we can monitor particle deposition in situ by measuring the zeta potential of a surface using a rotating disk electrode apparatus. The measured difference in iso-electric point of titania and both fluorine- and indium-tin oxide shown in this work indicates that we should have some control over the rate and extent of particle deposition. Currently, we have deposited titania nanoparticle layers which are several layers thick and consist of particles with diameters smaller than 10 nm; these tightly packed layers have applications as blocking layers to prevent unwanted shunts in dye solar cells.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125953197","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186240
Wentao Wang, Lei Wang, Fude Liu
Grain boundaries (GBs) play a major role in determining the device performance of in particular polycrystalline thin film solar cells including Si, CdTe and CIGS. Hydrogen passivation has been traditionally applied to passivate the defects at GBs. However, hydrogenated films such as amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si:H) are subject to light-induced degradation effects. In this study on multicrystalline (mc)-Si wafers, we found an excellent correlation between the grain misorientation and the corresponding electrical resistivity across grain boundaries. In particular, the charge transport across GBs was greatly enhanced after the wafers were properly treated in acetonitrile (CH3CN). The results were explained to be due to the more effective charge neutralization of polar molecules on GBs. These findings may help us achieve high-quality materials at low cost for high-efficient solar cells by improving the carrier transport and minimizing the carrier recombination. We also believe that this study will help us with a deeper understanding on GBs and their behaviors for the applications not only in photovoltaics, but also in other solid-state devices such as thin-film transistors.
{"title":"Grain boundary passivation with small polar molecules for photovoltaics","authors":"Wentao Wang, Lei Wang, Fude Liu","doi":"10.1109/PVSC.2011.6186240","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186240","url":null,"abstract":"Grain boundaries (GBs) play a major role in determining the device performance of in particular polycrystalline thin film solar cells including Si, CdTe and CIGS. Hydrogen passivation has been traditionally applied to passivate the defects at GBs. However, hydrogenated films such as amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si:H) are subject to light-induced degradation effects. In this study on multicrystalline (mc)-Si wafers, we found an excellent correlation between the grain misorientation and the corresponding electrical resistivity across grain boundaries. In particular, the charge transport across GBs was greatly enhanced after the wafers were properly treated in acetonitrile (CH3CN). The results were explained to be due to the more effective charge neutralization of polar molecules on GBs. These findings may help us achieve high-quality materials at low cost for high-efficient solar cells by improving the carrier transport and minimizing the carrier recombination. We also believe that this study will help us with a deeper understanding on GBs and their behaviors for the applications not only in photovoltaics, but also in other solid-state devices such as thin-film transistors.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125968162","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}
Pub Date : 2011-06-19DOI: 10.1109/PVSC.2011.6186610
A. G. Imenes, G. Yordanov, O. Midtgård, T. O. Saetre
The development of an outdoor test station for accurate in situ I-V curve measurements of photovoltaic (PV) modules is described. The modules are installed in an open-rack configuration at the University of Agder in Southern Norway. Seven new and three aged PV modules of different type and make are being tested, including mono-and multicrystalline silicon from differing manufacturing routes, triple-junction amorphous silicon, and CIS. Data acquisition is controlled with a multichannel electronic load system and LabVIEW software, recording high-resolution I-V curves at one-minute intervals. Between I-V curve sweeps, each module is operated at the maximum power point. Characteristic electrical parameters are extracted and stored together with values of module temperatures and in-plane solar irradiance, the latter recorded at sub-second resolution. The paper describes the experimental set-up in more detail, discusses some local environmental effects, and presents a sample of test results.
{"title":"Development of a test station for accurate in situ I-V curve measurements of photovoltaic modules in Southern Norway","authors":"A. G. Imenes, G. Yordanov, O. Midtgård, T. O. Saetre","doi":"10.1109/PVSC.2011.6186610","DOIUrl":"https://doi.org/10.1109/PVSC.2011.6186610","url":null,"abstract":"The development of an outdoor test station for accurate in situ I-V curve measurements of photovoltaic (PV) modules is described. The modules are installed in an open-rack configuration at the University of Agder in Southern Norway. Seven new and three aged PV modules of different type and make are being tested, including mono-and multicrystalline silicon from differing manufacturing routes, triple-junction amorphous silicon, and CIS. Data acquisition is controlled with a multichannel electronic load system and LabVIEW software, recording high-resolution I-V curves at one-minute intervals. Between I-V curve sweeps, each module is operated at the maximum power point. Characteristic electrical parameters are extracted and stored together with values of module temperatures and in-plane solar irradiance, the latter recorded at sub-second resolution. The paper describes the experimental set-up in more detail, discusses some local environmental effects, and presents a sample of test results.","PeriodicalId":373149,"journal":{"name":"2011 37th IEEE Photovoltaic Specialists Conference","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121956471","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}
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