Pub Date : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656700
G. Galbiati, V. Mihailetchi, A. Halm, L. J. Koduvelikulathu, R. Roescu, R. Kopecek, K. Peter, J. Libal
In this work high efficiency solar cells are fabricated with the use of low-cost industrially available technologies. The solar cell concept is called ZEBRA: a litho-free process in which standard 156×156 mm2 monocrystalline n-type Cz-Si are processed into high efficiency Interdigitated Back Contact (IBC) solar cells. In our first trial we obtained conversion efficiencies of more than 20% on solar cells with 239 cm2 area. With the help of a three-dimensional simulation of the device, a further improvement to more than 21.5% was demonstrated. We indentify the open-circuit voltage and the series resistance as the main losses to achieve the simulated efficiency. After an extensive optimization, targeting mainly the improvement of the fill factor, the cell results are presented in this work. The optimised solar cells show an improvement in the energy conversion efficiency of up to 21%. Furthermore, the simple metallization and the module interconnection designed for the ZEBRA cells allow for a bifacial application. Indoor and outdoor measurements on single-cell modules show an enhancement in the generated power of up to 12% at one sun front illumination conditions.
在这项工作中,高效率的太阳能电池是用低成本的工业技术制造的。太阳能电池概念被称为ZEBRA:一种无晶片工艺,其中标准156×156 mm2单晶n型Cz-Si被加工成高效率的Interdigitated Back Contact (IBC)太阳能电池。在我们的第一次试验中,我们在239平方厘米的太阳能电池上获得了超过20%的转换效率。通过对该装置的三维模拟,进一步提高了21.5%以上。我们确定了开路电压和串联电阻作为主要损耗来实现模拟效率。经过广泛的优化,主要针对填充因子的改善,在本工作中提出了细胞结果。优化后的太阳能电池的能量转换效率提高了21%。此外,为ZEBRA电池设计的简单金属化和模块互连允许双面应用。室内和室外对单电池模块的测量表明,在一个太阳正面照明条件下,产生的功率提高了12%。
{"title":"Large area back-contact back-junction solar cells with efficiency exceeding 21%","authors":"G. Galbiati, V. Mihailetchi, A. Halm, L. J. Koduvelikulathu, R. Roescu, R. Kopecek, K. Peter, J. Libal","doi":"10.1109/pvsc-vol2.2012.6656700","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656700","url":null,"abstract":"In this work high efficiency solar cells are fabricated with the use of low-cost industrially available technologies. The solar cell concept is called ZEBRA: a litho-free process in which standard 156×156 mm2 monocrystalline n-type Cz-Si are processed into high efficiency Interdigitated Back Contact (IBC) solar cells. In our first trial we obtained conversion efficiencies of more than 20% on solar cells with 239 cm2 area. With the help of a three-dimensional simulation of the device, a further improvement to more than 21.5% was demonstrated. We indentify the open-circuit voltage and the series resistance as the main losses to achieve the simulated efficiency. After an extensive optimization, targeting mainly the improvement of the fill factor, the cell results are presented in this work. The optimised solar cells show an improvement in the energy conversion efficiency of up to 21%. Furthermore, the simple metallization and the module interconnection designed for the ZEBRA cells allow for a bifacial application. Indoor and outdoor measurements on single-cell modules show an enhancement in the generated power of up to 12% at one sun front illumination conditions.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80229382","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656745
S. Grover, C. Teplin, Jian V. Li, D. Bobela, J. Bornstein, P. Schroeter, S. Johnston, H. Guthrey, P. Stradins, H. Branz, D. Young
We characterize heterojunction solar cells made from single-crystal silicon films grown heteroepitaxially using hot-wire chemical vapor deposition (HWCVD). Heteroepitaxy-induced dislocations limit the cell performance, providing a unique platform to study the device physics of thin crystal Si heterojunction solar cells. Hydrogen passivation of these dislocations enables an opencircuit voltage VOC close to 580 mV. However, dislocations are partially active, even after passivation. Using standard characterization methods, we compare the performance of heteroepitaxial absorbers with homoepitaxial absorbers that are free of dislocations. Heteroepitaxial cells have a smaller diffusion length and a larger ideality factor, indicating stronger recombination, which leads to inefficient current collection and a lower VOC than homoepitaxial cells. Modeling indicates that the recombination in the inversion layer of heterojunction cells made from defective absorbers is comparable with the overall recombination in the bulk. Temperature-dependent VOC measurements point to significant recombination at the interface that is attributable to the presence of dislocations.
{"title":"Device physics of heteroepitaxial film c-Si heterojunction solar cells","authors":"S. Grover, C. Teplin, Jian V. Li, D. Bobela, J. Bornstein, P. Schroeter, S. Johnston, H. Guthrey, P. Stradins, H. Branz, D. Young","doi":"10.1109/pvsc-vol2.2012.6656745","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656745","url":null,"abstract":"We characterize heterojunction solar cells made from single-crystal silicon films grown heteroepitaxially using hot-wire chemical vapor deposition (HWCVD). Heteroepitaxy-induced dislocations limit the cell performance, providing a unique platform to study the device physics of thin crystal Si heterojunction solar cells. Hydrogen passivation of these dislocations enables an opencircuit voltage VOC close to 580 mV. However, dislocations are partially active, even after passivation. Using standard characterization methods, we compare the performance of heteroepitaxial absorbers with homoepitaxial absorbers that are free of dislocations. Heteroepitaxial cells have a smaller diffusion length and a larger ideality factor, indicating stronger recombination, which leads to inefficient current collection and a lower VOC than homoepitaxial cells. Modeling indicates that the recombination in the inversion layer of heterojunction cells made from defective absorbers is comparable with the overall recombination in the bulk. Temperature-dependent VOC measurements point to significant recombination at the interface that is attributable to the presence of dislocations.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84996458","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656760
J. Melskens, A. Smets, M. Schouten, S. Eijt, H. Schut, M. Zeman
Temperature annealing is used as a tool to study the validity of network models for the nanostructure of hydrogenated amorphous silicon (a-Si:H) and its relation to defect states. The changes in the size of the dominant open volume deficiencies have been studied using Doppler broadening positron annihilation spectroscopy and Fourier transform infrared spectroscopy. It is shown that the dominant open volume deficiencies for as-deposited films are divacancies, which appear to agglomerate into larger open volume deficiencies up to 400 °C. Above this temperature, the largest open volume deficiencies are suggested to be released at the surface of the sample. Fourier transform photocurrent spectroscopy results indicate a dramatic increase in the density of various subgap defect state distributions during temperature annealing. In addition, at least four defect states have been identified. These findings cannot be directly explained by assuming solely dangling bonds as the dominant defects in a-Si:H. We discuss that a model based on an anisotropic disordered network with volume deficiencies does explain our findings better than the classical model based on a continuous random network with solely an isotropic distribution of coordination defects. The claim is made that next to dangling bonds not fully hydrogen-passivated vacancies are significantly contributing to the dominant defect states in a-Si:H.
{"title":"New insights in the nanostructure and defect states of hydrogenated amorphous silicon obtained by annealing","authors":"J. Melskens, A. Smets, M. Schouten, S. Eijt, H. Schut, M. Zeman","doi":"10.1109/pvsc-vol2.2012.6656760","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656760","url":null,"abstract":"Temperature annealing is used as a tool to study the validity of network models for the nanostructure of hydrogenated amorphous silicon (a-Si:H) and its relation to defect states. The changes in the size of the dominant open volume deficiencies have been studied using Doppler broadening positron annihilation spectroscopy and Fourier transform infrared spectroscopy. It is shown that the dominant open volume deficiencies for as-deposited films are divacancies, which appear to agglomerate into larger open volume deficiencies up to 400 °C. Above this temperature, the largest open volume deficiencies are suggested to be released at the surface of the sample. Fourier transform photocurrent spectroscopy results indicate a dramatic increase in the density of various subgap defect state distributions during temperature annealing. In addition, at least four defect states have been identified. These findings cannot be directly explained by assuming solely dangling bonds as the dominant defects in a-Si:H. We discuss that a model based on an anisotropic disordered network with volume deficiencies does explain our findings better than the classical model based on a continuous random network with solely an isotropic distribution of coordination defects. The claim is made that next to dangling bonds not fully hydrogen-passivated vacancies are significantly contributing to the dominant defect states in a-Si:H.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79834397","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656710
T. Kita, T. Maeda, Y. Harada
We have studied time-resolved intraband transition from the intermediate state to the continuum state of the conduction band in InAs/GaAs self-assembled quantum dots (QDs) embedded in a one-dimensional photonic cavity structure using a two-color photoexcitation spectroscopy. The photonic gap was tuned to enhance the excitation from the intermediate state to the conduction band, whose energy is selected to be less than the interband transition energy between the intermediate state and the quantized hole state. The photoluminescence intensity was observed to be dramatically reduced by selectively pumping carriers in the intermediate state. This effect has been analyzed by modeling detailed carrier relaxation process.
{"title":"Carrier dynamics in intermediate states of InAs/GaAs quantum dots embedded in photonic cavity structure","authors":"T. Kita, T. Maeda, Y. Harada","doi":"10.1109/pvsc-vol2.2012.6656710","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656710","url":null,"abstract":"We have studied time-resolved intraband transition from the intermediate state to the continuum state of the conduction band in InAs/GaAs self-assembled quantum dots (QDs) embedded in a one-dimensional photonic cavity structure using a two-color photoexcitation spectroscopy. The photonic gap was tuned to enhance the excitation from the intermediate state to the conduction band, whose energy is selected to be less than the interband transition energy between the intermediate state and the quantized hole state. The photoluminescence intensity was observed to be dramatically reduced by selectively pumping carriers in the intermediate state. This effect has been analyzed by modeling detailed carrier relaxation process.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86183954","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656715
H. Al-Thani, F. Hasoon
(In,Ga)2Se3 (IGS) thin films were deposited on Molybdenum (Mo) coated soda lime glass (Mo/SLG) substrates, using physical vapor deposition (PVD) technique, resembling only the first stage of the typical 3-stage growth process of CIGS thin film. The Mo thin films were sputtered on SLG substrates using DC planar magnetron sputtering at working gas (Ar) pressure that varies from 0.6 mT to 16 mT. The sputtering pressure of Mo thin films was varied in order to induce variations in the sputtered films' morphology and microstructure; as well as to subsequently induce variations in the rate of Na out-diffusion from SLG substrate. The IGS thin film deposition process was carried out with the same conditions of substrate temperature (Ts ∼ 400°C) and deposition rate that are required to accomplish the first stage of the complete typical 3-stage process of a CIGS thin film growth. To gain an understanding of the structural correlation between Mo and IGS films, and the effect of this correlation on Na out-diffusion process from SLG substrate. The Mo and IGS films' structures were examined by θ/2θ X-Ray Diffraction (XRD) characterization technique. Secondary-ion mass spectrometry (SIMS) was also applied to depth profile the Na, Se, and O in the IGS/Mo films. Whereas, the root-mean-square (RMS) surface roughness of both Mo and IGS films, was determined using Atomic Force Microscopy (AFM).
{"title":"Investigation of Na out-diffusion and structural properties of IGS film during three-stage growth process of CIGS thin film","authors":"H. Al-Thani, F. Hasoon","doi":"10.1109/pvsc-vol2.2012.6656715","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656715","url":null,"abstract":"(In,Ga)2Se3 (IGS) thin films were deposited on Molybdenum (Mo) coated soda lime glass (Mo/SLG) substrates, using physical vapor deposition (PVD) technique, resembling only the first stage of the typical 3-stage growth process of CIGS thin film. The Mo thin films were sputtered on SLG substrates using DC planar magnetron sputtering at working gas (Ar) pressure that varies from 0.6 mT to 16 mT. The sputtering pressure of Mo thin films was varied in order to induce variations in the sputtered films' morphology and microstructure; as well as to subsequently induce variations in the rate of Na out-diffusion from SLG substrate. The IGS thin film deposition process was carried out with the same conditions of substrate temperature (Ts ∼ 400°C) and deposition rate that are required to accomplish the first stage of the complete typical 3-stage process of a CIGS thin film growth. To gain an understanding of the structural correlation between Mo and IGS films, and the effect of this correlation on Na out-diffusion process from SLG substrate. The Mo and IGS films' structures were examined by θ/2θ X-Ray Diffraction (XRD) characterization technique. Secondary-ion mass spectrometry (SIMS) was also applied to depth profile the Na, Se, and O in the IGS/Mo films. Whereas, the root-mean-square (RMS) surface roughness of both Mo and IGS films, was determined using Atomic Force Microscopy (AFM).","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90949145","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2013.6656796
M. Woodhouse, A. Goodrich, R. Margolis, T. James, Martin Lokanc, R. Eggert
Given the need for humankind to implement more sustainable energy choices, it is crucial for energy systems such as PV to demonstrate success both soon and over the long-term quest for meaningful deployment. To that end, both the crystalline silicon and thin-film technologies have made, and continue to make, remarkable strides toward providing solutions that are quickly becoming more competitive against the traditional sources for power generation. But, within the thin-film segment of this industry, the highest demonstrated sunlight power conversion efficiencies have thus far come from technologies containing relatively rare constituent elements. These include tellurium in cadmium telluride, and indium and/or gallium in the CIS/ CIGS and III–V families of technologies. In this paper we show that the current global supply base for these three energy-critical elements is not sufficient for enabling energy-significant levels of deployment, but also show that every one of the thin-film PV technologies that we describe has the ability to absorb an increase in the price for each constituent element(s). This ability then leads to the possibility that the supply base for each element can be augmented.
{"title":"Supply-chain dynamics of tellurium, indium and gallium within the context of PV module manufacturing costs","authors":"M. Woodhouse, A. Goodrich, R. Margolis, T. James, Martin Lokanc, R. Eggert","doi":"10.1109/pvsc-vol2.2013.6656796","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2013.6656796","url":null,"abstract":"Given the need for humankind to implement more sustainable energy choices, it is crucial for energy systems such as PV to demonstrate success both soon and over the long-term quest for meaningful deployment. To that end, both the crystalline silicon and thin-film technologies have made, and continue to make, remarkable strides toward providing solutions that are quickly becoming more competitive against the traditional sources for power generation. But, within the thin-film segment of this industry, the highest demonstrated sunlight power conversion efficiencies have thus far come from technologies containing relatively rare constituent elements. These include tellurium in cadmium telluride, and indium and/or gallium in the CIS/ CIGS and III–V families of technologies. In this paper we show that the current global supply base for these three energy-critical elements is not sufficient for enabling energy-significant levels of deployment, but also show that every one of the thin-film PV technologies that we describe has the ability to absorb an increase in the price for each constituent element(s). This ability then leads to the possibility that the supply base for each element can be augmented.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79451821","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2012.6656798
Zhenhao Zhang, W. Witte, O. Kiowski, U. Lemmer, M. Powalla, Hendrik Holscher
Thin-film solar cells that are based on Cu(In,Ga)Se2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investigated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga content.
{"title":"Influence of the Ga content on the optical and electrical properties of CuIn1−xGaxSe2 thin-film solar cells","authors":"Zhenhao Zhang, W. Witte, O. Kiowski, U. Lemmer, M. Powalla, Hendrik Holscher","doi":"10.1109/pvsc-vol2.2012.6656798","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2012.6656798","url":null,"abstract":"Thin-film solar cells that are based on Cu(In,Ga)Se2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investigated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga content.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80706437","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2013.6656698
J. Yuventi
Photovoltaic systems have increased in both the quantity of installations and the size of installations over the past decade. As more utility-run systems are being constructed, it is important to consider the safety of operators and maintenance crew during the design and analyses phases. Unfortunately, one potential safety hazard, the electrical arc-flash, is not well understood for photovoltaic systems. The thermal energy released by this hazard can be significant, especially in large photovoltaic systems operating at high voltages and currents. This paper examines the conditions surrounding electric arc-flashes in photovoltaic systems based on typical designs. Using existing models for DC arc-flashes and basic circuit theory, equations and analysis techniques are developed to estimate the thermal energy that can be released if these hazards were to occur. These techniques can be used to determine the hazard-risk-category for the system components most at risk, until more empirical models are developed.
{"title":"Electric arc-flash energy calculations for photovoltaic systems","authors":"J. Yuventi","doi":"10.1109/pvsc-vol2.2013.6656698","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2013.6656698","url":null,"abstract":"Photovoltaic systems have increased in both the quantity of installations and the size of installations over the past decade. As more utility-run systems are being constructed, it is important to consider the safety of operators and maintenance crew during the design and analyses phases. Unfortunately, one potential safety hazard, the electrical arc-flash, is not well understood for photovoltaic systems. The thermal energy released by this hazard can be significant, especially in large photovoltaic systems operating at high voltages and currents. This paper examines the conditions surrounding electric arc-flashes in photovoltaic systems based on typical designs. Using existing models for DC arc-flashes and basic circuit theory, equations and analysis techniques are developed to estimate the thermal energy that can be released if these hazards were to occur. These techniques can be used to determine the hazard-risk-category for the system components most at risk, until more empirical models are developed.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90047706","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2013.6656783
N. R. Sorensen, E. Thomas, M. Quintana, S. Barkaszi, A. Rosenthal, Zhen Zhang, S. Kurtz
Thermal histories of inverter components were collected from operating inverters from several manufacturers and three locations. The data were analyzed to determine thermal profiles, the dependence on local conditions, and to assess the effect on inverter reliability. Inverter temperatures were shown to increase with the power dissipation of the inverters, follow diurnal and annual cycles, and have a dependence on wind speed. An accumulated damage model was applied to the temperature profiles and an example of using these data to predict reliability was explored.
{"title":"Thermal study of inverter components","authors":"N. R. Sorensen, E. Thomas, M. Quintana, S. Barkaszi, A. Rosenthal, Zhen Zhang, S. Kurtz","doi":"10.1109/pvsc-vol2.2013.6656783","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2013.6656783","url":null,"abstract":"Thermal histories of inverter components were collected from operating inverters from several manufacturers and three locations. The data were analyzed to determine thermal profiles, the dependence on local conditions, and to assess the effect on inverter reliability. Inverter temperatures were shown to increase with the power dissipation of the inverters, follow diurnal and annual cycles, and have a dependence on wind speed. An accumulated damage model was applied to the temperature profiles and an example of using these data to predict reliability was explored.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72972041","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 : 2013-01-01DOI: 10.1109/pvsc-vol2.2013.6656764
J. Munday
The limiting efficiency for photovoltaic energy conversion based on a semiconductor pn-junction is typically determined using the method of detailed balance put forth by Shockley and Queisser. Here we describe how this theory is altered in the presence of a photonic structure that is capable of modifying the absorption and emission of photons. By incorporating specifically designed photonic structures, higher maximum efficiencies can be achieved for low bandgap materials by restricting the absorption and emission of above bandgap photons. Similarly, restriction of the emission angle leads to increased optical concentration. We consider how both of these effects are modified in the presence of a non-ideal photonic structure.
{"title":"Designing photonic materials for effective bandgap modification and optical concentration in photovoltaics","authors":"J. Munday","doi":"10.1109/pvsc-vol2.2013.6656764","DOIUrl":"https://doi.org/10.1109/pvsc-vol2.2013.6656764","url":null,"abstract":"The limiting efficiency for photovoltaic energy conversion based on a semiconductor pn-junction is typically determined using the method of detailed balance put forth by Shockley and Queisser. Here we describe how this theory is altered in the presence of a photonic structure that is capable of modifying the absorption and emission of photons. By incorporating specifically designed photonic structures, higher maximum efficiencies can be achieved for low bandgap materials by restricting the absorption and emission of above bandgap photons. Similarly, restriction of the emission angle leads to increased optical concentration. We consider how both of these effects are modified in the presence of a non-ideal photonic structure.","PeriodicalId":6420,"journal":{"name":"2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81192643","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}