Pub Date : 2015-06-14DOI: 10.1109/PVSC.2015.7356037
M. A. Mohamed
This paper introduce a new approach, and associated algorithms, for the efficient approximation of a PV model by using dependent Thevenin equivalent circuit. The short linear combination of exponential function is used for constructing a mathematical function that is used to express the dependent Thevenin voltage source of a PV panel. The proposed method reduces the number of estimated parameters that are required to construct a PV model. This paper give an efficient approximation of a PV module which is very important to analysis of, individual a PV cells and complete systems, where it is practical to simulate large-scale PV systems using low-cost computer platforms. The effectiveness of the proposed PV model is demonstrated for different manufacturer panel models under different operating conditions.
{"title":"Efficient approximation of photovoltaic model using dependent thevenin equivalent circuit based on exponential sums function","authors":"M. A. Mohamed","doi":"10.1109/PVSC.2015.7356037","DOIUrl":"https://doi.org/10.1109/PVSC.2015.7356037","url":null,"abstract":"This paper introduce a new approach, and associated algorithms, for the efficient approximation of a PV model by using dependent Thevenin equivalent circuit. The short linear combination of exponential function is used for constructing a mathematical function that is used to express the dependent Thevenin voltage source of a PV panel. The proposed method reduces the number of estimated parameters that are required to construct a PV model. This paper give an efficient approximation of a PV module which is very important to analysis of, individual a PV cells and complete systems, where it is practical to simulate large-scale PV systems using low-cost computer platforms. The effectiveness of the proposed PV model is demonstrated for different manufacturer panel models under different operating conditions.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74438392","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 : 2014-06-08DOI: 10.1109/PVSC.2014.6925038
Yunping Wang, X. Ruan, Ying Li
When several solar units are combined into one branch in series, the multi-peak phenomenon of the output power of the branch would be present because of the bypass diode. By analysing the operation principle of the circuit, the number of peak point is decided by all short-circuit currents and maximum power points of all units in series. The way to calculating the number of peak point is designed. Based on the number of peak point a criterion for comparing the value of all peak points is put forward. The criterion put forward are validated by three experiments. This is interesting because the conclusion can make things convenient for designing method of tracking the maximum power of the circuit in series.
{"title":"An estimation method of maximum power point for solar units in series under uneven lighting conditions","authors":"Yunping Wang, X. Ruan, Ying Li","doi":"10.1109/PVSC.2014.6925038","DOIUrl":"https://doi.org/10.1109/PVSC.2014.6925038","url":null,"abstract":"When several solar units are combined into one branch in series, the multi-peak phenomenon of the output power of the branch would be present because of the bypass diode. By analysing the operation principle of the circuit, the number of peak point is decided by all short-circuit currents and maximum power points of all units in series. The way to calculating the number of peak point is designed. Based on the number of peak point a criterion for comparing the value of all peak points is put forward. The criterion put forward are validated by three experiments. This is interesting because the conclusion can make things convenient for designing method of tracking the maximum power of the circuit in series.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78303131","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}
In the process of optimizing solar cells a quantitative and depth-resolved elemental analysis of photovoltaic thin films is strongly required. Regarding Cu(In,Ga)Se2 (CIGS) thin film solar cells, depth dependent stoichometric changes of Ga and In are of great interest because the In/Ga ratio has a large effect on solar cell efficiencies. In this paper we investigate the elemental composition of CIGS thin film solar cells based on secondary ion intensities in Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) depth profiling, providing high sensitivities and high spatial resolution. Quantification of the data is obtained by comparison to X-ray Photoelectron Spectroscopy (XPS) depth profiles. The detection of MCs+-clusters is used for semiquantitative elemental analysis of CIGS thin films. Correlation plots of the intensities of GaCs+ and InCs+ indicate that there is no relevant matrix effect for In and Ga due to changes in stoichiometry in the layer. Additional high resolution Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements show a strong correlation between the ratio of the bulk concentrations of Ga and In and the ratio of integrated ToF-SIMS intensities of GaCs+ and InCs+ therefore supporting the quantitative interpretation of MCs+ data.
{"title":"Quantitative elemental analysis of photovoltaic Cu(In,Ga)Se2 thin films using MCs+ clusters","authors":"K. Kaufmann, S. Wahl, S. Meyer, C. Hagendorf","doi":"10.1002/sia.4950","DOIUrl":"https://doi.org/10.1002/sia.4950","url":null,"abstract":"In the process of optimizing solar cells a quantitative and depth-resolved elemental analysis of photovoltaic thin films is strongly required. Regarding Cu(In,Ga)Se2 (CIGS) thin film solar cells, depth dependent stoichometric changes of Ga and In are of great interest because the In/Ga ratio has a large effect on solar cell efficiencies. In this paper we investigate the elemental composition of CIGS thin film solar cells based on secondary ion intensities in Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) depth profiling, providing high sensitivities and high spatial resolution. Quantification of the data is obtained by comparison to X-ray Photoelectron Spectroscopy (XPS) depth profiles. The detection of MCs+-clusters is used for semiquantitative elemental analysis of CIGS thin films. Correlation plots of the intensities of GaCs+ and InCs+ indicate that there is no relevant matrix effect for In and Ga due to changes in stoichiometry in the layer. Additional high resolution Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements show a strong correlation between the ratio of the bulk concentrations of Ga and In and the ratio of integrated ToF-SIMS intensities of GaCs+ and InCs+ therefore supporting the quantitative interpretation of MCs+ data.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","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":"88038079","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 : 2012-10-04DOI: 10.1109/PVSC.2012.6317880
B. Gorman, H. Guthrey, M. Al‐Jassim
Characterization of defect locations and their effects on transport in polycrystalline Si photovoltaics is readily accomplished using optical and electrical characterization. Information on the elemental nature of these defects is more difficult due to both the low concentrations and highly localized positions. This work demonstrates the ability to locate and elementally analyze electronic defects in these devices using correlative electron microscopy and spectroscopy within a focused ion beam specimen preparation tool followed by 3-D atom probe tomography.
{"title":"Quantification of atomic scale defects in poly Si PV devices using atom probe tomography","authors":"B. Gorman, H. Guthrey, M. Al‐Jassim","doi":"10.1109/PVSC.2012.6317880","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317880","url":null,"abstract":"Characterization of defect locations and their effects on transport in polycrystalline Si photovoltaics is readily accomplished using optical and electrical characterization. Information on the elemental nature of these defects is more difficult due to both the low concentrations and highly localized positions. This work demonstrates the ability to locate and elementally analyze electronic defects in these devices using correlative electron microscopy and spectroscopy within a focused ion beam specimen preparation tool followed by 3-D atom probe tomography.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83948929","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 : 2012-10-04DOI: 10.1109/PVSC.2012.6317874
K. Choudhury, Yanyan Cao, J. Caspar, W. Farneth, Qijie Guo, A. Ionkin, L. Johnson, Meijun Lu, I. Malajovich, D. Radu, H. D. Rosenfeld, Wei Wu
We present results on the characterization of a highly efficient CZTSSe solar cell fabricated using a solution-based process, aiming to gain a better understanding of its efficiency-limiting causes. Under red light illumination, we observed a red-kink in the current-density versus voltage (J-V) curve, likely due to a persistent photoconductivity in the buffer layer. Temperature-dependent J-V analysis suggests that interface recombination is the dominant loss mechanism. Defect analysis using admittance spectroscopy (AS) shows a single bulk defect level at ~63 meV and may be attributed to copper vacancy (VCu). The carrier concentration of the device determined using drive-level capacitance profiling (DLCP) is ~2.5×1016 cm-3.
{"title":"Characterization and understanding of performance losses in a highly efficient solution-processed CZTSSe thin-film solar cell","authors":"K. Choudhury, Yanyan Cao, J. Caspar, W. Farneth, Qijie Guo, A. Ionkin, L. Johnson, Meijun Lu, I. Malajovich, D. Radu, H. D. Rosenfeld, Wei Wu","doi":"10.1109/PVSC.2012.6317874","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317874","url":null,"abstract":"We present results on the characterization of a highly efficient CZTSSe solar cell fabricated using a solution-based process, aiming to gain a better understanding of its efficiency-limiting causes. Under red light illumination, we observed a red-kink in the current-density versus voltage (J-V) curve, likely due to a persistent photoconductivity in the buffer layer. Temperature-dependent J-V analysis suggests that interface recombination is the dominant loss mechanism. Defect analysis using admittance spectroscopy (AS) shows a single bulk defect level at ~63 meV and may be attributed to copper vacancy (VCu). The carrier concentration of the device determined using drive-level capacitance profiling (DLCP) is ~2.5×1016 cm-3.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76746169","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 : 2012-10-04DOI: 10.1109/PVSC.2012.6318062
B. Omrane, J. Aristizabal, C. Landrock, Y. Chuo, D. Fournier, S. V. Grayli, B. Kaminska
We report on the optimization of poly(3-hexylthiopene) and [6,6]-phenyl C61 butyric acid methyl ester bulk heterojunction photovoltaics using indium tin oxide anode and metallic indium cathode. The devices are fabricated, tested, and stored at ambient atmosphere, without encapsulation. By tuning the spin coating conditions for the hole-transport and the photoactive layers, along with a combination of mechanical pressure and annealing conditions during the cathode deposition, a 3-fold improvement is achieved, while maintaining devices stability. Consequently, the cells undergo a less than 10% loss in power conversion efficiency after 200 days.
{"title":"Enhancement of indium-based organic photovoltaics","authors":"B. Omrane, J. Aristizabal, C. Landrock, Y. Chuo, D. Fournier, S. V. Grayli, B. Kaminska","doi":"10.1109/PVSC.2012.6318062","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318062","url":null,"abstract":"We report on the optimization of poly(3-hexylthiopene) and [6,6]-phenyl C61 butyric acid methyl ester bulk heterojunction photovoltaics using indium tin oxide anode and metallic indium cathode. The devices are fabricated, tested, and stored at ambient atmosphere, without encapsulation. By tuning the spin coating conditions for the hole-transport and the photoactive layers, along with a combination of mechanical pressure and annealing conditions during the cathode deposition, a 3-fold improvement is achieved, while maintaining devices stability. Consequently, the cells undergo a less than 10% loss in power conversion efficiency after 200 days.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83470708","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 : 2012-10-04DOI: 10.1109/PVSC.2012.6318140
B. Nadimpally, S. Guduru, R. Mangu, S. Rajaputra, V. Singh
Nanowire arrays of copper indium diselenide (CuInSe2) were fabricated using an electrochemical deposition process. Custom anodized aluminum oxide (AAO) membranes on a glass substrate with a Ti interlayer served as templates for this electrodeposition. Typical diameter of electrodeposited nanowires was 60 nm although process parameters for anodization could be varied in a controlled way to obtain pore diameters as low as 20 nm. Elemental composition of these CuInSe2 nanowires on titanium substrate was studied using energy dispersive x-ray analysis (EDX). The atomic percentage ratio for as deposited nanowires was Cu: In: Se= 1:1.16:2.53. The electrolyte composition and other deposition parameters were optimized in order to yield slightly In-rich structures because it is well known that such films result in better photovoltaic devices. It is thought that, with material properties ideally suited for photovoltaic (PV) applications, the use of CIS nanowire arrays would enable a new generation of PV device architectures.
{"title":"Vertically aligned CuInSe2 nanowire arrays on titanium coated glass substrates for photovoltaic applications","authors":"B. Nadimpally, S. Guduru, R. Mangu, S. Rajaputra, V. Singh","doi":"10.1109/PVSC.2012.6318140","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318140","url":null,"abstract":"Nanowire arrays of copper indium diselenide (CuInSe2) were fabricated using an electrochemical deposition process. Custom anodized aluminum oxide (AAO) membranes on a glass substrate with a Ti interlayer served as templates for this electrodeposition. Typical diameter of electrodeposited nanowires was 60 nm although process parameters for anodization could be varied in a controlled way to obtain pore diameters as low as 20 nm. Elemental composition of these CuInSe2 nanowires on titanium substrate was studied using energy dispersive x-ray analysis (EDX). The atomic percentage ratio for as deposited nanowires was Cu: In: Se= 1:1.16:2.53. The electrolyte composition and other deposition parameters were optimized in order to yield slightly In-rich structures because it is well known that such films result in better photovoltaic devices. It is thought that, with material properties ideally suited for photovoltaic (PV) applications, the use of CIS nanowire arrays would enable a new generation of PV device architectures.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80033447","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 : 2012-06-03DOI: 10.1109/PVSC.2012.6317947
N. Bosco, T. Silverman, S. Kurtz
It is commonly understood that thermal cycling at high temperature ramp rates may activate unrepresentative failure mechanisms. Increasing the temperature ramp rate of thermal cycling, however, could dramatically reduce the test time required to achieve an equivalent amount of thermal fatigue damage, thereby reducing overall test time. Therefore, the effect of temperature ramp rate on physical damage in the CPV die-attach is investigated. Finite Element Model (FEM) simulations of thermal fatigue and thermal cycling experiments are made to determine if the amount of damage calculated results in a corresponding amount of physical damage measured to the die-attach for a variety of fast temperature ramp rates. Preliminary experimental results are in good agreement with simulations and reinforce the potential of increasing temperature ramp rates. Characterization of the microstructure and resulting fatigue crack in the die-attach suggest a similar failure mechanism across all ramp rates tested.
{"title":"On the effect of ramp rate in damage accumulation of the CPV die-attach","authors":"N. Bosco, T. Silverman, S. Kurtz","doi":"10.1109/PVSC.2012.6317947","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6317947","url":null,"abstract":"It is commonly understood that thermal cycling at high temperature ramp rates may activate unrepresentative failure mechanisms. Increasing the temperature ramp rate of thermal cycling, however, could dramatically reduce the test time required to achieve an equivalent amount of thermal fatigue damage, thereby reducing overall test time. Therefore, the effect of temperature ramp rate on physical damage in the CPV die-attach is investigated. Finite Element Model (FEM) simulations of thermal fatigue and thermal cycling experiments are made to determine if the amount of damage calculated results in a corresponding amount of physical damage measured to the die-attach for a variety of fast temperature ramp rates. Preliminary experimental results are in good agreement with simulations and reinforce the potential of increasing temperature ramp rates. Characterization of the microstructure and resulting fatigue crack in the die-attach suggest a similar failure mechanism across all ramp rates tested.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73639168","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 : 2012-06-03DOI: 10.1109/PVSC.2012.6318128
S. Siah, Y. Lee, R. Brandt, T. Buonassisi
Formation of low-resistance ohmic contacts to novel earth abundant absorber materials is required to minimize resistive power losses in photovoltaic devices. We first show that the specific contact resistivity (ρc) of 3 inert metals (Au, Ag and Pd) to copper (I) oxide (Cu2O) thin films can be reduced significantly through the application of a doped Cu2O functional layer. Specific contact resistivity as low as 1.1×10-4 Ω·cm2 is observed for Pd to nitrogen-doped (N-doped) Cu2O films. This is the lowest-ever reported ρc to date for Cu2O films. Temperature-dependent current-voltage (IVT) measurements indicate that thermionic emission dominates for nominally undoped films whilst field emission dominates for N-doped films. Additionally, IVT suggests that ρc does not depend on metal type for N-doped films due to the formation of a tunneling junction. Lastly, we demonstrate that low contact resistivity can be achieved on N-doped Cu2O films using Earth-abundant metals such as Cu and Ni.
{"title":"Low-resistance earth-abundant metal contacts to nitrogen-doped cuprous oxide thin films","authors":"S. Siah, Y. Lee, R. Brandt, T. Buonassisi","doi":"10.1109/PVSC.2012.6318128","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318128","url":null,"abstract":"Formation of low-resistance ohmic contacts to novel earth abundant absorber materials is required to minimize resistive power losses in photovoltaic devices. We first show that the specific contact resistivity (ρ<sub>c</sub>) of 3 inert metals (Au, Ag and Pd) to copper (I) oxide (Cu<sub>2</sub>O) thin films can be reduced significantly through the application of a doped Cu<sub>2</sub>O functional layer. Specific contact resistivity as low as 1.1×10<sup>-4</sup> Ω·cm<sup>2</sup> is observed for Pd to nitrogen-doped (N-doped) Cu<sub>2</sub>O films. This is the lowest-ever reported ρ<sub>c</sub> to date for Cu<sub>2</sub>O films. Temperature-dependent current-voltage (IVT) measurements indicate that thermionic emission dominates for nominally undoped films whilst field emission dominates for N-doped films. Additionally, IVT suggests that ρ<sub>c</sub> does not depend on metal type for N-doped films due to the formation of a tunneling junction. Lastly, we demonstrate that low contact resistivity can be achieved on N-doped Cu<sub>2</sub>O films using Earth-abundant metals such as Cu and Ni.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73895420","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 : 2012-06-03DOI: 10.1109/PVSC.2012.6318044
Kyungsun Ryu, A. Upadhyaya, Y. Ok, H. Xu, L. Metin, A. Rohatgi
Formation of low-cost boron-doped emitters for mass production of n-type silicon solar cells is a major challenge in the PV industry. In this paper, we report on commercially viable screen printing technology to create boron emitters. A screen-printed boron emitter and phosphorus implanted back surface field were formed simultaneously by a co-annealing process. Front and back surfaces were passivated by chemically-grown oxide/PECVD silicon nitride stack. Front and back contacts were formed by traditional screen printing and firing processes with silver/aluminum grid on front and local silver contacts on the rear. This resulted in 19.3 % high efficient large are (239cm2) n-type solar cells with an open-circuit voltage Voc of 653 mV, short-circuit current density Jsc of 37.7 mA/cm2, and fill factor FF of 78.3 %. Co-diffusion and co-firing reduced the number of processing steps compared to the traditional technologies like BBr3 diffusion. Detailed cell analysis gave a bulk lifetime of over 1 ms, the emitter saturation current density J0e of 101 fA/cm2, and base saturation current density J0b of 259 fA/cm2 respectively. This demonstrates the potential of this novel technology for production of low-cost high-efficiency cells.
{"title":"High efficiency n-type solar cells with screen-printed boron emitters and ion-implanted back surface field","authors":"Kyungsun Ryu, A. Upadhyaya, Y. Ok, H. Xu, L. Metin, A. Rohatgi","doi":"10.1109/PVSC.2012.6318044","DOIUrl":"https://doi.org/10.1109/PVSC.2012.6318044","url":null,"abstract":"Formation of low-cost boron-doped emitters for mass production of n-type silicon solar cells is a major challenge in the PV industry. In this paper, we report on commercially viable screen printing technology to create boron emitters. A screen-printed boron emitter and phosphorus implanted back surface field were formed simultaneously by a co-annealing process. Front and back surfaces were passivated by chemically-grown oxide/PECVD silicon nitride stack. Front and back contacts were formed by traditional screen printing and firing processes with silver/aluminum grid on front and local silver contacts on the rear. This resulted in 19.3 % high efficient large are (239cm2) n-type solar cells with an open-circuit voltage Voc of 653 mV, short-circuit current density Jsc of 37.7 mA/cm2, and fill factor FF of 78.3 %. Co-diffusion and co-firing reduced the number of processing steps compared to the traditional technologies like BBr3 diffusion. Detailed cell analysis gave a bulk lifetime of over 1 ms, the emitter saturation current density J0e of 101 fA/cm2, and base saturation current density J0b of 259 fA/cm2 respectively. This demonstrates the potential of this novel technology for production of low-cost high-efficiency cells.","PeriodicalId":6318,"journal":{"name":"2012 38th IEEE Photovoltaic Specialists Conference","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73995251","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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