Sb_(2)Se_(3)solar cells have achieved a power conversion efficiency(PCE)of over 10%.However,the serious open-circuit voltage deficit(VOC-deificit),induced by the hard-to-control crystal orientation and heterojunction ...Sb_(2)Se_(3)solar cells have achieved a power conversion efficiency(PCE)of over 10%.However,the serious open-circuit voltage deficit(VOC-deificit),induced by the hard-to-control crystal orientation and heterojunction interface reaction,limits the PCE of vapor transport deposition(VTD)processed Sb_(2)Se_(3)solar cells.To overcome the VOC-deficit problem of VTD processed Sb_(2)Se_(3)solar cells,herein,an in-situ bandgap regulation strategy is innovatively proposed to prepare a wide band gap Sb2(S,Se)3seed layer(WBSL)at CdS/Sb_(2)Se_(3)heterojunction interface to improve the PCE of Sb_(2)Se_(3)solar cells.The analysis results show that the introduced Sb2(S,Se)3seed layer can enhance the[001]orientation of Sb_(2)Se_(3)thin films,broaden the band gap of heterojunction interface,and realize a"Spike-like"conduction band alignment with ΔE_(c)=0.11 eV.In addition,thanks to the suppressed CdS/Sb_(2)Se_(3)interface reaction after WBSL application,the depletion region width of Sb_(2)Se_(3)solar cells is widened,and the quality of CdS/Sb_(2)Se_(3)interface and the carrier transporting performance of Sb_(2)Se_(3)solar cells are significantly improved as well.Moreover,the harmful Se vacancy defects near the front interface of Sb_(2)Se_(3)solar cells can be greatly diminished by WBSL.Finally,the PCE of Sb_(2)Se_(3)solar cells is improved from 7.0%to 7.6%;meanwhile the VOCis increased to 466 mV which is the highest value for the VTD derived Sb_(2)Se_(3)solar cells.This work will provide a valuable reference for the interface and orientation regulation of antimony-based chalcogenide solar cells.展开更多
The effect of the valence band tail width on the open circuit voltage of P3HT：PCBM bulk heterojunction solar cell is investigated by using the AMPS-1D computer program. An effective medium model with exponential vale...The effect of the valence band tail width on the open circuit voltage of P3HT：PCBM bulk heterojunction solar cell is investigated by using the AMPS-1D computer program. An effective medium model with exponential valence and conduction band tail states is used to simulate the photovoltaic cell. The simulation result shows that the open circuit voltage depends Iinearly on the logarithm of the generation rate and the slope depends on the width of the valence band tail. The open circuit voltage decreases with the increasing width of the band tail. The dark and light ideality factors increase with the width of the valence band tail.展开更多
The objective of this study is to find an effective method to improve Voc without Jsc loss for Cu2ZnSnSe4 （CZTSe） thin film solar cells, which have been fabricated by the one step co-evaporation technique. Surface s...The objective of this study is to find an effective method to improve Voc without Jsc loss for Cu2ZnSnSe4 （CZTSe） thin film solar cells, which have been fabricated by the one step co-evaporation technique. Surface sulfurization of CZTSe thin films is carried out by using one technique that does not utilize toxic H2S gas; a sequential evaporation of SnS after CZTSe deposition and the annealing of CZTSe thin films in selenium vapor. A Cu2ZnSn（S, Se）4 （CZTSSe） thin layer is grown on the surface of the CZTSe thin film after the annealing. The conversion efficiency of the completed device is improved due to the enhancement of Voc, which could be attributed to the formation of a hole-recombination barrier at the surface or the passivation of the surface and grain boundary by S incorporation.展开更多
The physical fundamentals and influences upon electrode materials＇ open-circuit voltage （OCV） and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate t...The physical fundamentals and influences upon electrode materials＇ open-circuit voltage （OCV） and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries （LIBs）, and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.展开更多
基金supported by the National Natural Science Foundation of China(62305064)the Research Start-up Fund for Young Teachers of Fuzhou University(602592)+1 种基金the Young and Middleaged Teacher Education Research Project of Fujian Province(JAT220011)the Fujian Science&Technology Innovation Laboratory Optoelectronic Information of China(Grant No.2021ZZ124).
文摘Sb_(2)Se_(3)solar cells have achieved a power conversion efficiency(PCE)of over 10%.However,the serious open-circuit voltage deficit(VOC-deificit),induced by the hard-to-control crystal orientation and heterojunction interface reaction,limits the PCE of vapor transport deposition(VTD)processed Sb_(2)Se_(3)solar cells.To overcome the VOC-deficit problem of VTD processed Sb_(2)Se_(3)solar cells,herein,an in-situ bandgap regulation strategy is innovatively proposed to prepare a wide band gap Sb2(S,Se)3seed layer(WBSL)at CdS/Sb_(2)Se_(3)heterojunction interface to improve the PCE of Sb_(2)Se_(3)solar cells.The analysis results show that the introduced Sb2(S,Se)3seed layer can enhance the[001]orientation of Sb_(2)Se_(3)thin films,broaden the band gap of heterojunction interface,and realize a"Spike-like"conduction band alignment with ΔE_(c)=0.11 eV.In addition,thanks to the suppressed CdS/Sb_(2)Se_(3)interface reaction after WBSL application,the depletion region width of Sb_(2)Se_(3)solar cells is widened,and the quality of CdS/Sb_(2)Se_(3)interface and the carrier transporting performance of Sb_(2)Se_(3)solar cells are significantly improved as well.Moreover,the harmful Se vacancy defects near the front interface of Sb_(2)Se_(3)solar cells can be greatly diminished by WBSL.Finally,the PCE of Sb_(2)Se_(3)solar cells is improved from 7.0%to 7.6%;meanwhile the VOCis increased to 466 mV which is the highest value for the VTD derived Sb_(2)Se_(3)solar cells.This work will provide a valuable reference for the interface and orientation regulation of antimony-based chalcogenide solar cells.
文摘The effect of the valence band tail width on the open circuit voltage of P3HT：PCBM bulk heterojunction solar cell is investigated by using the AMPS-1D computer program. An effective medium model with exponential valence and conduction band tail states is used to simulate the photovoltaic cell. The simulation result shows that the open circuit voltage depends Iinearly on the logarithm of the generation rate and the slope depends on the width of the valence band tail. The open circuit voltage decreases with the increasing width of the band tail. The dark and light ideality factors increase with the width of the valence band tail.
基金Supported by the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20120031110039
文摘The objective of this study is to find an effective method to improve Voc without Jsc loss for Cu2ZnSnSe4 （CZTSe） thin film solar cells, which have been fabricated by the one step co-evaporation technique. Surface sulfurization of CZTSe thin films is carried out by using one technique that does not utilize toxic H2S gas; a sequential evaporation of SnS after CZTSe deposition and the annealing of CZTSe thin films in selenium vapor. A Cu2ZnSn（S, Se）4 （CZTSSe） thin layer is grown on the surface of the CZTSe thin film after the annealing. The conversion efficiency of the completed device is improved due to the enhancement of Voc, which could be attributed to the formation of a hole-recombination barrier at the surface or the passivation of the surface and grain boundary by S incorporation.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325206 and 51372228)National Basic Research Program of China(Grant No.2012CB932900)Shanghai Pujiang Program,China(Grant No.14PJ1403900)
文摘The physical fundamentals and influences upon electrode materials＇ open-circuit voltage （OCV） and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries （LIBs）, and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.
