Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744499
N. Biderman, S. Novak, T. Laursen, R. Matyi, R. Sundaramoorthy, Gary Dufresne, J. Wax, M. Gardner, D. Fobare, D. Metacarpa, P. Haldar, J. Lloyd
Diffusivity and activation energy of cadmium in copper indium gallium diselenide (CuInGaSe2 or CIGS) thin films were investigated by annealing solar-grade SLG/Mo/CIGS/CdS samples of two different CIGS thicknesses at temperatures between 150° C and 325° C. Diffusion profiles of cadmium volume and grain boundary were investigated by dual-beam time-of-flight secondary ion mass spectroscopy. A relationship between the cadmium's volume and grain boundary diffusion coefficients and their activation energies at a given annealing temperature was established using LeClaire's grain boundary diffusion model. The data also provide evidence that cadmium diffusion may be strongly modulated by a gallium gradient seen both laterally at the interface and in the bulk in solar-grade CIGS material.
{"title":"Diffusion activation energy of cadmium in thin film CuInGaSe2","authors":"N. Biderman, S. Novak, T. Laursen, R. Matyi, R. Sundaramoorthy, Gary Dufresne, J. Wax, M. Gardner, D. Fobare, D. Metacarpa, P. Haldar, J. Lloyd","doi":"10.1109/PVSC.2013.6744499","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744499","url":null,"abstract":"Diffusivity and activation energy of cadmium in copper indium gallium diselenide (CuInGaSe2 or CIGS) thin films were investigated by annealing solar-grade SLG/Mo/CIGS/CdS samples of two different CIGS thicknesses at temperatures between 150° C and 325° C. Diffusion profiles of cadmium volume and grain boundary were investigated by dual-beam time-of-flight secondary ion mass spectroscopy. A relationship between the cadmium's volume and grain boundary diffusion coefficients and their activation energies at a given annealing temperature was established using LeClaire's grain boundary diffusion model. The data also provide evidence that cadmium diffusion may be strongly modulated by a gallium gradient seen both laterally at the interface and in the bulk in solar-grade CIGS material.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"58 1","pages":"1836-1841"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90694185","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744460
L. Kranz, R. Schmitt, C. Gretener, J. Perrenoud, F. Pianezzi, A. Uhl, D. Keller, S. Buecheler, A. Tiwari
CdTe solar cells are conventionally grown in superstrate configuration. However, the growth in substrate configuration offers more control of junction properties as recrystallization of CdTe and junction formation with CdS can be decoupled. In this paper the influence of various annealing treatment conditions of the CdS layer on its morphology and phase and on the device properties is presented. The presence of CdCl2 during this annealing treatment is important for the phase change of the CdS layer to hexagonal wurtzite and for high efficiencies. A CdCl2 treatment of the CdS at 360 °C improves the efficiency of the device without the adverse effect of pinhole formation in the CdS. CdTe solar cells in substrate configuration with more than 13% efficiency are achieved as a progress towards 14% efficiency.
{"title":"Progress towards 14% efficient CdTe solar cells in substrate configuration","authors":"L. Kranz, R. Schmitt, C. Gretener, J. Perrenoud, F. Pianezzi, A. Uhl, D. Keller, S. Buecheler, A. Tiwari","doi":"10.1109/PVSC.2013.6744460","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744460","url":null,"abstract":"CdTe solar cells are conventionally grown in superstrate configuration. However, the growth in substrate configuration offers more control of junction properties as recrystallization of CdTe and junction formation with CdS can be decoupled. In this paper the influence of various annealing treatment conditions of the CdS layer on its morphology and phase and on the device properties is presented. The presence of CdCl2 during this annealing treatment is important for the phase change of the CdS layer to hexagonal wurtzite and for high efficiencies. A CdCl2 treatment of the CdS at 360 °C improves the efficiency of the device without the adverse effect of pinhole formation in the CdS. CdTe solar cells in substrate configuration with more than 13% efficiency are achieved as a progress towards 14% efficiency.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"37 1","pages":"1644-1648"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89850352","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744124
J. Serra, P. Bellanger, K. Lobato, R. Martini, M. Debucquoy, J. Poortmans
The decrease in wafer thickness seen as a route to cost reductions has raised a growing interest in techniques that allow the preparation of thin wafers without kerf loss. The Slim-cut process [1] is one of these new techniques and comprises mainly three stages: a stress layer deposition step on the top of a monocrystalline silicon sample, a heating step necessary to induce the stress on the silicon sample and detach a thin silicon layer, and a third step to clean the stress-inducing layer to obtain a silicon foil adapted to the fabrication of solar cells. One of the major problems of this technology consists in finding a stress layer that induces a sufficiently high contraction in order to achieve a rupture of the silicon without contamination of the foil. In this work we present a comparison between thin foils obtained by Slim-cut, using three different stress layers: i) a double screen printed Silver/Aluminum layer, ii) a dispensed epoxy paste, iii) an electrodeposited Nickel metallization. Results on lifetime measurements indicate that some of the stress layers, although capable of inducing large stress, severely degrade lifetime of the foil.
{"title":"Comparative study of stress inducing layers to produce kerfless thin wafers by the Slim-cut technique","authors":"J. Serra, P. Bellanger, K. Lobato, R. Martini, M. Debucquoy, J. Poortmans","doi":"10.1109/PVSC.2013.6744124","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744124","url":null,"abstract":"The decrease in wafer thickness seen as a route to cost reductions has raised a growing interest in techniques that allow the preparation of thin wafers without kerf loss. The Slim-cut process [1] is one of these new techniques and comprises mainly three stages: a stress layer deposition step on the top of a monocrystalline silicon sample, a heating step necessary to induce the stress on the silicon sample and detach a thin silicon layer, and a third step to clean the stress-inducing layer to obtain a silicon foil adapted to the fabrication of solar cells. One of the major problems of this technology consists in finding a stress layer that induces a sufficiently high contraction in order to achieve a rupture of the silicon without contamination of the foil. In this work we present a comparison between thin foils obtained by Slim-cut, using three different stress layers: i) a double screen printed Silver/Aluminum layer, ii) a dispensed epoxy paste, iii) an electrodeposited Nickel metallization. Results on lifetime measurements indicate that some of the stress layers, although capable of inducing large stress, severely degrade lifetime of the foil.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"1 1","pages":"0177-0180"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90869072","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 : 2013-06-16DOI: 10.4229/28thEUPVSEC2013-5BV.4.37
H. Beyer, T. O. Saetre, G. Yordanov
aSi modules show large variations in their response to the incoming irradiance as measured by broad-band irradiance sensors, making the check and prediction of their performance difficult when only broad-band data are available. One approach to overcome this difficulty is given by the use of detailed models to estimate the irradiance spectra from the broad-band data. Here, it is tested to what degree the detailed modeling could be substituted by a semi-empirical approach to reflect the modules response based on but the information on direct and diffuse irradiance and solar geometry. The model performance is measured by its capability to give the correct monthly mean short-circuit current together with a reasonable R2 value of the scatter of modeled and measured data. A first test of a respective model has shown reasonable results.
{"title":"Using broad-band irradiance data to model the short circuit response of aSi modules","authors":"H. Beyer, T. O. Saetre, G. Yordanov","doi":"10.4229/28thEUPVSEC2013-5BV.4.37","DOIUrl":"https://doi.org/10.4229/28thEUPVSEC2013-5BV.4.37","url":null,"abstract":"aSi modules show large variations in their response to the incoming irradiance as measured by broad-band irradiance sensors, making the check and prediction of their performance difficult when only broad-band data are available. One approach to overcome this difficulty is given by the use of detailed models to estimate the irradiance spectra from the broad-band data. Here, it is tested to what degree the detailed modeling could be substituted by a semi-empirical approach to reflect the modules response based on but the information on direct and diffuse irradiance and solar geometry. The model performance is measured by its capability to give the correct monthly mean short-circuit current together with a reasonable R2 value of the scatter of modeled and measured data. A first test of a respective model has shown reasonable results.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"17 1","pages":"0751-0753"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73514494","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744325
A. Martí, E. Antolín, P. García‐Linares, I. Ramiro, E. López, I. Tobías, A. Luque
We introduce one trivial but puzzling solar cell structure. It consists of a high bandgap pn junction (top cell) grown on a substrate of lower bandgap. Let us assume, for example, that the bandgap of the top cell is 1.85 eV (Al0.3Ga0.7As) and the bandgap of the substrate is 1.42 eV (GaAs). Is the open-circuit of the top cell limited to 1.42 V or to 1.85 V? If the answer is “1.85 V” we could then make the mind experiment in which we illuminate the cell with 1.5 eV photons (notice these photons would only be absorbed in the substrate). If we admit that these photons can generate photocurrent, then because we have also admitted that the voltage is limited to 1.85 V, it might be possible that the electron-hole pairs generated by these photons were extracted at 1.6 V for example. However, if we do so, the principles of thermodynamics could be violated because we would be extracting more energy from the photon than the energy it initially had. How can we then solve this puzzle?
我们介绍一个微不足道但令人费解的太阳能电池结构。它由生长在低带隙衬底上的高带隙pn结(顶电池)组成。例如,我们假设顶电池的带隙为1.85 eV (Al0.3Ga0.7As),衬底的带隙为1.42 eV (GaAs)。顶部电池的开路是否限制在1.42 V或1.85 V?如果答案是“1.85 V”,那么我们可以做一个心灵实验,用1.5 eV的光子照亮电池(注意这些光子只会被衬底吸收)。如果我们承认这些光子可以产生光电流,那么因为我们也承认电压限制在1.85 V,所以有可能这些光子产生的电子-空穴对在1.6 V时被提取出来。然而,如果我们这样做,热力学原理可能会被违反,因为我们将从光子中提取比它最初拥有的能量更多的能量。那么我们如何解决这个难题呢?
{"title":"A puzzling solar cell structure: An exercise to get insight on intermediate band solar cells","authors":"A. Martí, E. Antolín, P. García‐Linares, I. Ramiro, E. López, I. Tobías, A. Luque","doi":"10.1109/PVSC.2013.6744325","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744325","url":null,"abstract":"We introduce one trivial but puzzling solar cell structure. It consists of a high bandgap pn junction (top cell) grown on a substrate of lower bandgap. Let us assume, for example, that the bandgap of the top cell is 1.85 eV (Al0.3Ga0.7As) and the bandgap of the substrate is 1.42 eV (GaAs). Is the open-circuit of the top cell limited to 1.42 V or to 1.85 V? If the answer is “1.85 V” we could then make the mind experiment in which we illuminate the cell with 1.5 eV photons (notice these photons would only be absorbed in the substrate). If we admit that these photons can generate photocurrent, then because we have also admitted that the voltage is limited to 1.85 V, it might be possible that the electron-hole pairs generated by these photons were extracted at 1.6 V for example. However, if we do so, the principles of thermodynamics could be violated because we would be extracting more energy from the photon than the energy it initially had. How can we then solve this puzzle?","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"129 1","pages":"1069-1073"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76679296","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744272
Huan-Liang Tsai, C. Hsu, Chao-Yia Yang
This paper presents the design and performance evaluation of a building integrated photovoltaic/thermal and heat pump water heater (BIPVT/HPWH) system. The system performance is evaluated using the proposed BIPVT/HPWH model with a user-friendly graphic user interface like Simulink block libraries. Integrating with a HPWH system, the BIPVT modules are designed for both solar electricity and thermal collector that offer heat and power consumption of heat pump for water heating. This makes refrigerant efficiently evaporated by solar energy and PV efficiency consequently enhanced with waste heat removal by refrigerant. The results of performance evaluation reveal that the average coefficient of performance (COP) achieves up to 6.7.
{"title":"Design and performance evaluation of building integrated PVT and heat pump water heating (BIPVT/HPWH) system","authors":"Huan-Liang Tsai, C. Hsu, Chao-Yia Yang","doi":"10.1109/PVSC.2013.6744272","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744272","url":null,"abstract":"This paper presents the design and performance evaluation of a building integrated photovoltaic/thermal and heat pump water heater (BIPVT/HPWH) system. The system performance is evaluated using the proposed BIPVT/HPWH model with a user-friendly graphic user interface like Simulink block libraries. Integrating with a HPWH system, the BIPVT modules are designed for both solar electricity and thermal collector that offer heat and power consumption of heat pump for water heating. This makes refrigerant efficiently evaporated by solar energy and PV efficiency consequently enhanced with waste heat removal by refrigerant. The results of performance evaluation reveal that the average coefficient of performance (COP) achieves up to 6.7.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"273 1","pages":"0821-0823"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76784124","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744958
Zhang Jia, Lv Fang, L. Hailing, W. Wenjing, Liu Xiuqiong, Ma Liyun
Fluoride emissions have strict rules to supervise for its poison to the human and environment. HF is used by the photovoltaic manufacturing industry in 3 manufacturing sections including high-purity polysilicon, silicon wafer and PV cell & module, which will generate fluoride waste. This paper focused on the fluoride emission in the waste water and the clean production of crystalline PV manufacturing. The fluoride generation processes and abatement method in the waste water, as well as the clean production of 3 manufacturing sections in crystalline PV manufacturing were analyzed. Abatement system is needed to remove the fluoride (F-) generated by PV production and after treatment, the fluoride won't cause the water environmental problems. In high-purity polysilicon and wafer manufacturing, the fluoride emission amount depended on the manufacturing technique level and raw silicon material quality. Clean production is very important for the PV manufacturing development, which can make the PV industry double green. The research can lay the foundation for the environmental impact assessment and management of photovoltaic manufacturing industry in China.
{"title":"Fluorinated wastewater abatement method and clean production in crystalline silicon photovoltaic manufacturing","authors":"Zhang Jia, Lv Fang, L. Hailing, W. Wenjing, Liu Xiuqiong, Ma Liyun","doi":"10.1109/PVSC.2013.6744958","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744958","url":null,"abstract":"Fluoride emissions have strict rules to supervise for its poison to the human and environment. HF is used by the photovoltaic manufacturing industry in 3 manufacturing sections including high-purity polysilicon, silicon wafer and PV cell & module, which will generate fluoride waste. This paper focused on the fluoride emission in the waste water and the clean production of crystalline PV manufacturing. The fluoride generation processes and abatement method in the waste water, as well as the clean production of 3 manufacturing sections in crystalline PV manufacturing were analyzed. Abatement system is needed to remove the fluoride (F-) generated by PV production and after treatment, the fluoride won't cause the water environmental problems. In high-purity polysilicon and wafer manufacturing, the fluoride emission amount depended on the manufacturing technique level and raw silicon material quality. Clean production is very important for the PV manufacturing development, which can make the PV industry double green. The research can lay the foundation for the environmental impact assessment and management of photovoltaic manufacturing industry in China.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"17 1","pages":"2399-2403"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78509837","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744404
S. Gangam, A. Jeffries, D. Fenning, B. Lai, J. Maser, T. Buonassisi, C. Honsberg, M. Bertoni
The vast majority of photovoltaic materials are highly sensitive to the presence of inhomogeneously distributed nanoscale defects, which commonly regulate the overall performance of the devices. The defects can take the form of impurities, stoichiometry variations, microstructural misalignments, and secondary phases - the majority of which are created during solar cell processing. Scientific understanding of these defects and development of defect-engineering techniques have the potential to significantly increase cell efficiencies, as well as provide a science-based approach to increase the competitiveness for the US PV industry on a dollar per installed kWh criterion. For the case of Cu(In, Ga)Se2 devices for example, the theoretically limit sits at 30.5% efficiency [1], thus, surpassing DOE's SunShot goals for cost-competitive solar power. However, to date, CIGS laboratory scale cells have been reported to achieve only 20.3% efficiencies and modules have not crossed the 15 % certified efficiency barrier. Recent reports have suggested that these record cells are limited by non-ideal recombination and, more specifically, by an increased saturation current that seems to originate from the particular defect chemistry at structural defects. In order to understand the severe efficiency limitations that currently affect solar cell materials, it is necessary to understand in detail the role of defects and their interactions under actual operating and processing conditions. In this work we propose to develop a high-temperature, in-situ stage for X-ray microscopes, with the capabilities of temperature and ambient control. Here, we provide insight into the design and preliminary testing at the Advanced Photon Source with beam sizes ≈100nm.
{"title":"In-situ stage development for high-temperature X-ray nanocharacterization of defects in solar cells","authors":"S. Gangam, A. Jeffries, D. Fenning, B. Lai, J. Maser, T. Buonassisi, C. Honsberg, M. Bertoni","doi":"10.1109/PVSC.2013.6744404","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744404","url":null,"abstract":"The vast majority of photovoltaic materials are highly sensitive to the presence of inhomogeneously distributed nanoscale defects, which commonly regulate the overall performance of the devices. The defects can take the form of impurities, stoichiometry variations, microstructural misalignments, and secondary phases - the majority of which are created during solar cell processing. Scientific understanding of these defects and development of defect-engineering techniques have the potential to significantly increase cell efficiencies, as well as provide a science-based approach to increase the competitiveness for the US PV industry on a dollar per installed kWh criterion. For the case of Cu(In, Ga)Se2 devices for example, the theoretically limit sits at 30.5% efficiency [1], thus, surpassing DOE's SunShot goals for cost-competitive solar power. However, to date, CIGS laboratory scale cells have been reported to achieve only 20.3% efficiencies and modules have not crossed the 15 % certified efficiency barrier. Recent reports have suggested that these record cells are limited by non-ideal recombination and, more specifically, by an increased saturation current that seems to originate from the particular defect chemistry at structural defects. In order to understand the severe efficiency limitations that currently affect solar cell materials, it is necessary to understand in detail the role of defects and their interactions under actual operating and processing conditions. In this work we propose to develop a high-temperature, in-situ stage for X-ray microscopes, with the capabilities of temperature and ambient control. Here, we provide insight into the design and preliminary testing at the Advanced Photon Source with beam sizes ≈100nm.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"6 1","pages":"1394-1395"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78582543","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744975
Haoting Shen, Yu A. Yuwen, Xin Wang, J. I. Ramírez, Yuanyuan Li, Y. Ke, C. Kendrick, N. Podraza, T. Jackson, E. Dickey, T. Mayer, J. Redwing
Radial junction Si pillar array solar cells based on the heterojunction with intrinsic thin layer (HIT) structure were fabricated from p-type crystal Si (c-Si) wafers of different doping densities. The HIT structure consisting of intrinsic/n-type hydrogenated amorphous Si (a-Si:H) deposited by plasma-enhanced chemical vapor deposition (PECVD) at low temperature (200°C) was found to effectively passivate the high surface area of the p-type Si pillar arrays resulting in open circuit voltages (Voc>0.5) comparable to that obtained on planar devices. At high c-Si doping densities (>1018 cm-3), the short-circuit current density (Jsc) and energy conversion efficiency of the radial junction devices were higher than those of the planar devices demonstrating improved carrier collection in the radial junction structure.
{"title":"Effect of c-Si doping density on heterojunction with intrinsic thin layer (HIT) radial junction solar cells","authors":"Haoting Shen, Yu A. Yuwen, Xin Wang, J. I. Ramírez, Yuanyuan Li, Y. Ke, C. Kendrick, N. Podraza, T. Jackson, E. Dickey, T. Mayer, J. Redwing","doi":"10.1109/PVSC.2013.6744975","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744975","url":null,"abstract":"Radial junction Si pillar array solar cells based on the heterojunction with intrinsic thin layer (HIT) structure were fabricated from p-type crystal Si (c-Si) wafers of different doping densities. The HIT structure consisting of intrinsic/n-type hydrogenated amorphous Si (a-Si:H) deposited by plasma-enhanced chemical vapor deposition (PECVD) at low temperature (200°C) was found to effectively passivate the high surface area of the p-type Si pillar arrays resulting in open circuit voltages (Voc>0.5) comparable to that obtained on planar devices. At high c-Si doping densities (>1018 cm-3), the short-circuit current density (Jsc) and energy conversion efficiency of the radial junction devices were higher than those of the planar devices demonstrating improved carrier collection in the radial junction structure.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"50 1","pages":"2466-2469"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75064971","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 : 2013-06-16DOI: 10.1109/PVSC.2013.6744304
R. van Haaren, M. Morjaria, V. Fthenakis
Balancing authorities are currently exploring options for transferring the additional ramping costs of conventional generators in the grid back to the variable energy resources using the principle of cost causation. In this paper, we present a characterization of short-term variability in power output of seven large-scale PV plants in the United States and Canada with a total installed capacity of 445 MW (AC). In addition, we will present a methodology for investigating the use of energy storage for cloud-induced ramp rate control, which is developed with time-series PV plant power output.
{"title":"Utility scale PV plant variability and energy storage for ramp rate control","authors":"R. van Haaren, M. Morjaria, V. Fthenakis","doi":"10.1109/PVSC.2013.6744304","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744304","url":null,"abstract":"Balancing authorities are currently exploring options for transferring the additional ramping costs of conventional generators in the grid back to the variable energy resources using the principle of cost causation. In this paper, we present a characterization of short-term variability in power output of seven large-scale PV plants in the United States and Canada with a total installed capacity of 445 MW (AC). In addition, we will present a methodology for investigating the use of energy storage for cloud-induced ramp rate control, which is developed with time-series PV plant power output.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"65 1","pages":"0973-0979"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75370340","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}