Pub Date : 2013-06-16DOI: 10.1109/PVSC.2013.6744489
K. Schillinger, S. Janz, S. Reber
This work describes the processing of recrystallized silicon thin-film solar cells and its typical defects. Zircon (ZrSiO4) ceramic substrates of technical grade with potential production costs of <; 20 €/m2 were used. Those substrates were encapsulated in crystalline silicon carbide, deposited by atmospheric pressure chemical vapor deposition (APCVD). The active silicon layers were also formed using APCVD. Zone-melting recrystallization (ZMR) was used to enlarge Si grains. Si films crystallized on SiC show characteristic Σ3 twin grain boundaries parallel to the growth direction. The Si crystals achieve widths up to several mm and lengths of several cm. Solar cells made from such material achieved open circuit voltages up to 566 mV on zircon and up to 600 mV on equally processed mc-Si.
{"title":"Recrystallized silicon thin-film solar cells on zircon ceramics","authors":"K. Schillinger, S. Janz, S. Reber","doi":"10.1109/PVSC.2013.6744489","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744489","url":null,"abstract":"This work describes the processing of recrystallized silicon thin-film solar cells and its typical defects. Zircon (ZrSiO4) ceramic substrates of technical grade with potential production costs of <; 20 €/m2 were used. Those substrates were encapsulated in crystalline silicon carbide, deposited by atmospheric pressure chemical vapor deposition (APCVD). The active silicon layers were also formed using APCVD. Zone-melting recrystallization (ZMR) was used to enlarge Si grains. Si films crystallized on SiC show characteristic Σ3 twin grain boundaries parallel to the growth direction. The Si crystals achieve widths up to several mm and lengths of several cm. Solar cells made from such material achieved open circuit voltages up to 566 mV on zircon and up to 600 mV on equally processed mc-Si.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"22 1","pages":"1784-1787"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88912678","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.2013.6745028
S. Bakhshi, S. Collins, C. Ferekides, A. Takshi
The structure and quality of the TiO2 is crucial for achieving high efficiency in dye-sensitized solar cells (DSCs). In this work we have studied the effect of annealing temperature, TiCl4 concentration/ treatment time and the number of the TiO2 layers on the performance of a DSC device. It is found that increasing the annealing temperature and treatment time with application of diluted TiCl4 increased the efficiency. These items along with including a bi-layer semiconductor led to a 30% performance increase in comparison to the original solar cell just by considering the best concentration and time product for TiCl4 treatment step. The enhancement in the performance is likely due to high porosity of the semiconductor layer. Also, the lessened TiCl4 concentration decreases the harmful effects of the harsh solution but still allows for band edge improvement. Lastly, the bi-layer consisted of transparent and opaque TiO2 paste. The first consist of 15-20nm particles and the latter comprises of ~100 nm particles. Each contributes to enhancement, as the dye and sunlight have greater absorption and scattering capabilities. Currently in progress is the synthesis and fabrication of new dyes, for compatibility efforts with the semiconductor.
{"title":"Study the effect of TiO2 annealing and TiCl4 treatment on the performance of dye-sensitized solar cells","authors":"S. Bakhshi, S. Collins, C. Ferekides, A. Takshi","doi":"10.1109/PVSC.2013.6745028","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6745028","url":null,"abstract":"The structure and quality of the TiO2 is crucial for achieving high efficiency in dye-sensitized solar cells (DSCs). In this work we have studied the effect of annealing temperature, TiCl4 concentration/ treatment time and the number of the TiO2 layers on the performance of a DSC device. It is found that increasing the annealing temperature and treatment time with application of diluted TiCl4 increased the efficiency. These items along with including a bi-layer semiconductor led to a 30% performance increase in comparison to the original solar cell just by considering the best concentration and time product for TiCl4 treatment step. The enhancement in the performance is likely due to high porosity of the semiconductor layer. Also, the lessened TiCl4 concentration decreases the harmful effects of the harsh solution but still allows for band edge improvement. Lastly, the bi-layer consisted of transparent and opaque TiO2 paste. The first consist of 15-20nm particles and the latter comprises of ~100 nm particles. Each contributes to enhancement, as the dye and sunlight have greater absorption and scattering capabilities. Currently in progress is the synthesis and fabrication of new dyes, for compatibility efforts with the semiconductor.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"41 1","pages":"2694-2697"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89156035","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.2013.6744162
V. Venkatachalapathy, A. Galeckas, A. Kuznetsov
We report on time-resolved and steady state photoluminescence (PL) studies of strained ZnxCd1-xO/ZnO MQW structures grown on c-plane and r-plane sapphire substrates by Metaloranic Vapor Phase Epitaxy. The high crystalline quality of all MQW structures was confirmed by X-ray diffraction measurements. No emission related to ZnO barriers could be resolved in PL spectra implying effective carrier confinement in the quantum wells. The estimated built-in electric field from optical transition is of the order of ~ 1.75 MV/cm. The observed spectral and carrier lifetime variations are discussed in terms of quantum confinement and internal electric field modulation induced by strain.
{"title":"CdO/ZnO multiple quantum wells as components for next generation solar cells","authors":"V. Venkatachalapathy, A. Galeckas, A. Kuznetsov","doi":"10.1109/PVSC.2013.6744162","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744162","url":null,"abstract":"We report on time-resolved and steady state photoluminescence (PL) studies of strained ZnxCd1-xO/ZnO MQW structures grown on c-plane and r-plane sapphire substrates by Metaloranic Vapor Phase Epitaxy. The high crystalline quality of all MQW structures was confirmed by X-ray diffraction measurements. No emission related to ZnO barriers could be resolved in PL spectra implying effective carrier confinement in the quantum wells. The estimated built-in electric field from optical transition is of the order of ~ 1.75 MV/cm. The observed spectral and carrier lifetime variations are discussed in terms of quantum confinement and internal electric field modulation induced by strain.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"255 1","pages":"0337-0342"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89183931","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: 10.4229/28THEUPVSEC2013-3DV.1.6
Chaho Ahn, S. Varlamov, Kyung Kim, M. Green
Liquid phase crystalline silicon solar cell on glass with lightly doped absorber layer has degradations in Voc and FF after contact bake. Experimental results provide evidence of elimination of Voc degradation with selective high concentration doping near absorber contacts. Comparison of cell performance between baseline processed and selectively doped samples are provided. After 43 days, the enhanced cell performance continued, with negligible deviations. In addition, a low series resistance of 1.5 Ω was obtained.
{"title":"Selective high concentration doping of boron near absorber contacts of a laser crystallized silicon thin-film solar cell on glass","authors":"Chaho Ahn, S. Varlamov, Kyung Kim, M. Green","doi":"10.4229/28THEUPVSEC2013-3DV.1.6","DOIUrl":"https://doi.org/10.4229/28THEUPVSEC2013-3DV.1.6","url":null,"abstract":"Liquid phase crystalline silicon solar cell on glass with lightly doped absorber layer has degradations in Voc and FF after contact bake. Experimental results provide evidence of elimination of Voc degradation with selective high concentration doping near absorber contacts. Comparison of cell performance between baseline processed and selectively doped samples are provided. After 43 days, the enhanced cell performance continued, with negligible deviations. In addition, a low series resistance of 1.5 Ω was obtained.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"214 1","pages":"1318-1321"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89185221","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.2013.6745049
T. Ohshima, Shin‐ichiro Sato, Tetsuya Nakamura, M. Imaizumi, T. Sugaya, K. Matsubara, S. Niki, A. Takeda, Y. Okano
The degradation behaviors of GaAs PiN solar cells with and without quantum dot (QD) layers due to proton irradiation were compared. The GaAs PiN structures either with or without 50 self-aligned In0.4Ga0.6As layers were grown by Molecular Beam Epitaxy (MBE). The QD and non QD solar cells were irradiated with 150 keV and 3 MeV protons, and their electrical performance under AM0 was in-situ measured. Annealing behavior of the electrical characteristics at room temperature was also investigated after the proton irradiation.
{"title":"Electrical performance degradation of GaAs solar cells with InGaAs quantum dot layers due to proton irradiation","authors":"T. Ohshima, Shin‐ichiro Sato, Tetsuya Nakamura, M. Imaizumi, T. Sugaya, K. Matsubara, S. Niki, A. Takeda, Y. Okano","doi":"10.1109/PVSC.2013.6745049","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6745049","url":null,"abstract":"The degradation behaviors of GaAs PiN solar cells with and without quantum dot (QD) layers due to proton irradiation were compared. The GaAs PiN structures either with or without 50 self-aligned In0.4Ga0.6As layers were grown by Molecular Beam Epitaxy (MBE). The QD and non QD solar cells were irradiated with 150 keV and 3 MeV protons, and their electrical performance under AM0 was in-situ measured. Annealing behavior of the electrical characteristics at room temperature was also investigated after the proton irradiation.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"64 1","pages":"2779-2783"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83141282","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.2013.6744876
M. Topič, B. Lipovšek, A. Čampa, J. Krč, J. Sites
Limitations in performance of single-junction thin film solar cells are reviewed. Conversion efficiency in single junction solar cells is systematically analyzed in terms of energy conversion efficiency, electrical efficiency and optical efficiency. The analysis reveals a strong dependence of limitations in single junction solar cells on the band-gap of the absorber. In the case of CIGS solar cells, the band gap can be varied from 1.04 ev to 1.7 eV, which allows considerable opportunity to optimize for both band gap and the associated temperature coefficient.
{"title":"Thin film solar cell performance limits and potential","authors":"M. Topič, B. Lipovšek, A. Čampa, J. Krč, J. Sites","doi":"10.1109/PVSC.2013.6744876","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744876","url":null,"abstract":"Limitations in performance of single-junction thin film solar cells are reviewed. Conversion efficiency in single junction solar cells is systematically analyzed in terms of energy conversion efficiency, electrical efficiency and optical efficiency. The analysis reveals a strong dependence of limitations in single junction solar cells on the band-gap of the absorber. In the case of CIGS solar cells, the band gap can be varied from 1.04 ev to 1.7 eV, which allows considerable opportunity to optimize for both band gap and the associated temperature coefficient.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"1 1","pages":"2052-2055"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83157036","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.2013.6744158
B. Sturmberg, K. Dossou, L. Botten, A. Asatryan, C. Poulton, R. McPhedran, C. D. de Sterke
Nanowire arrays are the focus of considerable research for incorporation into next generation solar cells. For these structures to be economically viable they must be designed to achieve high efficiencies in the presence of fabrication variations. Here we report on a systematic study of arrays of clustered nanowires, which reveals how the underlying physics of absorption enhancement in nanowire arrays is altered by the introduction of positional disorder. We find that positional disorder in fact enhances absorption efficiency over the majority of the parameter space due to the formation of additional modes in the structure and subsequently broadened absorption peaks.
{"title":"Positional disorder in nanowire array photovoltaics","authors":"B. Sturmberg, K. Dossou, L. Botten, A. Asatryan, C. Poulton, R. McPhedran, C. D. de Sterke","doi":"10.1109/PVSC.2013.6744158","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744158","url":null,"abstract":"Nanowire arrays are the focus of considerable research for incorporation into next generation solar cells. For these structures to be economically viable they must be designed to achieve high efficiencies in the presence of fabrication variations. Here we report on a systematic study of arrays of clustered nanowires, which reveals how the underlying physics of absorption enhancement in nanowire arrays is altered by the introduction of positional disorder. We find that positional disorder in fact enhances absorption efficiency over the majority of the parameter space due to the formation of additional modes in the structure and subsequently broadened absorption peaks.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"111 1","pages":"0322-0325"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80733934","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.2013.6744147
J. Gandhi, C. Kim, W. Kirk
The lattice misfit at the island-cap interface in two In0.15Ga0.85As p-i-n devices, with 5 layers of InAs quantum dots (QDs), was modified by depositing 2.1 and 3.2 ML of InAs while maintaining near identical capping layers. The device with 35 ± 3 nm island size distribution exhibited photoluminescence activity in the near infra-red range from 975 to 1150 nm while the device with 42 ± 12 nm size islands recorded lower PL intensity over a narrower range of 1000-1100 nm suggesting (a) increased island-cap interface misfit, (b) truncation of the islands, and (c) generation of structural defects.
{"title":"Island-cap interface misfit modulated carrier mechanisms in p-i-n epitaxial quantum dot photovoltaic devices","authors":"J. Gandhi, C. Kim, W. Kirk","doi":"10.1109/PVSC.2013.6744147","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744147","url":null,"abstract":"The lattice misfit at the island-cap interface in two In0.15Ga0.85As p-i-n devices, with 5 layers of InAs quantum dots (QDs), was modified by depositing 2.1 and 3.2 ML of InAs while maintaining near identical capping layers. The device with 35 ± 3 nm island size distribution exhibited photoluminescence activity in the near infra-red range from 975 to 1150 nm while the device with 42 ± 12 nm size islands recorded lower PL intensity over a narrower range of 1000-1100 nm suggesting (a) increased island-cap interface misfit, (b) truncation of the islands, and (c) generation of structural defects.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"33 1","pages":"0281-0283"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83180025","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.2013.6744334
Guibin Chen, K. Yu, L. Reichertz, W. Walukiewicz
We have studied structural, electrical and optical properties of ternary Cd1-xMgxO alloy thin films synthesized by radio frequency magnetron sputtering method with Mg content as high as x=0.44. We found that only a fraction (50-60%) of Mg is incorporated as substitutional Mg contributing to the modification of the electronic structure of the alloy. The electrical and optical results of the Cd1-xMgxO alloys are analyzed in terms of a large upward shift of the conduction band edge with increasing Mg content. The rapid increase of the optical band gap offers a potential of using Cd-rich CdMgO alloys as transparent conductors for photovoltaics.
{"title":"Material properties of Cd1−xMgxO transparent conductors","authors":"Guibin Chen, K. Yu, L. Reichertz, W. Walukiewicz","doi":"10.1109/PVSC.2013.6744334","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744334","url":null,"abstract":"We have studied structural, electrical and optical properties of ternary Cd1-xMgxO alloy thin films synthesized by radio frequency magnetron sputtering method with Mg content as high as x=0.44. We found that only a fraction (50-60%) of Mg is incorporated as substitutional Mg contributing to the modification of the electronic structure of the alloy. The electrical and optical results of the Cd1-xMgxO alloys are analyzed in terms of a large upward shift of the conduction band edge with increasing Mg content. The rapid increase of the optical band gap offers a potential of using Cd-rich CdMgO alloys as transparent conductors for photovoltaics.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"18 6 1","pages":"1105-1109"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83194147","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.2013.6744974
K. Schmieder, A. Gerger, Z. Pulwin, Li Wang, M. Diaz, M. Curtin, C. Ebert, Anthony Lochtefeld, R. Opila, A. Barnett
GaAsP solar cells have been grown on Si substrates facilitated by a SiGe graded buffer layer. Here, single-junction p+/n GaAsP and tandem n+/p GaAsP/SiGe solar cells are reported with an interest in improving efficiency by evaluation of the III-V device passivation layers and pathways to their optimization. Solar cells with varying window thicknesses are reported for both structures and assist in directing focus of future research. The GaAsP/SiGe on Si tandem solar cell demonstrates a result towards AM1.5G 20.8% AR-corrected efficiency.
GaAsP太阳能电池已在硅衬底上生长,并由SiGe渐变缓冲层促进。本文报道了单结p+/n GaAsP和串联n+/p GaAsP/SiGe太阳能电池,并通过评估III-V器件钝化层和优化途径来提高效率。具有不同窗厚的太阳能电池被报道用于结构和帮助指导未来研究的重点。GaAsP/SiGe on Si串联太阳能电池的ar校正效率为AM1.5G,达到20.8%。
{"title":"GaInP window layers for GaAsP on SiGe/Si single and dual-junction solar cells","authors":"K. Schmieder, A. Gerger, Z. Pulwin, Li Wang, M. Diaz, M. Curtin, C. Ebert, Anthony Lochtefeld, R. Opila, A. Barnett","doi":"10.1109/PVSC.2013.6744974","DOIUrl":"https://doi.org/10.1109/PVSC.2013.6744974","url":null,"abstract":"GaAsP solar cells have been grown on Si substrates facilitated by a SiGe graded buffer layer. Here, single-junction p+/n GaAsP and tandem n+/p GaAsP/SiGe solar cells are reported with an interest in improving efficiency by evaluation of the III-V device passivation layers and pathways to their optimization. Solar cells with varying window thicknesses are reported for both structures and assist in directing focus of future research. The GaAsP/SiGe on Si tandem solar cell demonstrates a result towards AM1.5G 20.8% AR-corrected efficiency.","PeriodicalId":6350,"journal":{"name":"2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)","volume":"88 1","pages":"2462-2465"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83203108","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}