In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor film...In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.展开更多
The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the ...The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the increase in the Zn/Sn ratio can slightly narrow the energy band gap to extend the light absorption range and improve the photocurrent. Optimal Zn/Sn ratio of 1.39 in CZTSSe film is obtained with the least secondary phase, the lowest defect density, and the longest charge recombination lifetime. Up to 10.1% photoelectric conversion efficiency has been achieved by this composition regulation.展开更多
采用共溅射法结合后硒化成功制备出CZTSSe薄膜,主要研究了不同的硒化温度对CZTSSe薄膜与电池性能的影响。分别采用X射线衍射仪、拉曼光谱仪、扫描电子显微镜、紫外-可见-近红外分光光度计、霍尔效应测量仪及数字电源表对不同硒化温度下...采用共溅射法结合后硒化成功制备出CZTSSe薄膜,主要研究了不同的硒化温度对CZTSSe薄膜与电池性能的影响。分别采用X射线衍射仪、拉曼光谱仪、扫描电子显微镜、紫外-可见-近红外分光光度计、霍尔效应测量仪及数字电源表对不同硒化温度下制备的CZTSSe薄膜的结构、形貌、光电与太阳电池性能进行了表征与分析。结果表明,当硒化温度为580℃时,CZTSSe薄膜的结晶性最好,薄膜表面均匀致密且其电阻率和载流子浓度达到最小值和最大值,分别为1.57Ω·cm和8.2×10^(17)cm^(-3),该硒化温度下制备得到的CZTSSe太阳电池的短路电流和转换效率最高达到30.68 m A/cm^2和5.17%。相对于550℃和600℃硒化温度下的CZTSSe太阳电池,其光电转换效率分别提高了36%和6%。另外,随着硒化温度的升高,CZTSSe薄膜在XRD中的(112)峰位和Raman中的A1模式振动峰位都向小衍射角和短波数方向移动,薄膜的禁带宽度也从1.26 e V减小至1.21 e V。展开更多
VSe2 is with high electrical conductivity and high work function,thus it is beneficial for the carrier transport in the optoelectronic devices.However,the performance and mechanism of its effect on the photoelectronic...VSe2 is with high electrical conductivity and high work function,thus it is beneficial for the carrier transport in the optoelectronic devices.However,the performance and mechanism of its effect on the photoelectronic devices conversion efficiency is still beyond understood.In this work,we fabricate VSe2 film between back contact and absorber layer Cu2ZnSn(S,Se)4(CZTSSe)film.We demonstrate that the VSe2 film in back contact region increases solar cell efficiency by 39%.Besides improving the carrier transport in the back contact region,the increasing can also be attributed to the reduction of the decomposition reaction of CZTSSe during the nucleation of CZTSSe as VSe2 fabricated between back contact and absorber layer.The present work not only provides an effective method to improve the performance of the optoelectronic device,but also shows an attractive application of metallic TMDs in optoelectronic device and solar cell energy generation.展开更多
Cu2ZnSn（S,Se）4 （CZTSSe） is considered as the promising absorbing layer materials for solar cells due to its earth-abundant constituents and excellent semiconductor properties. Through solution-processing, such as ...Cu2ZnSn（S,Se）4 （CZTSSe） is considered as the promising absorbing layer materials for solar cells due to its earth-abundant constituents and excellent semiconductor properties. Through solution-processing, such as various printing methods, the fabrication of high perfor- mance CZTSSe solar cell could be applied to mass production with extremely low manufacturing cost and high yield speed. To better fulfill this goal, environmentalfriendly inks/solutions are optimum for further reducing the capital investment on instrument, personnel and environmental safety. In this review, we summarized the recent development of CZTSSe thin films solar cells fabricated with benign solvents, such as water and ethanol. The disperse system can be classified to the true solution （consisting of molecules） and the colloidal suspension （consisting ofnanoparticles）.Three strategies for stabilization （i.e., physical method, chemical capping and self- stabilization） are proposed to prepare homogeneous and stable colloidal nanoinks. The one-pot self-stabilization method stands as an optimum route for preparing benign inks for its low impurity involvement and simple procedure. As-prepared CZTSSe inks would be deposited onto substrates to form thin films through spin-coating, spraying, electrodeposition or successive ionic layer adsorption and reaction （SILAR） method, followed by annealing in a chalcogen （S- or Se-containing） atmosphere to fabricate absorber. The efficiency of CZTSSe solar cell fabricated with benign solvents can also be enhanced by constituent adjustments, doping, surface treatments and blocking layers modifications, etc., and the deeper research will promise it a comparable performance to the non- benign CZTSSe systems.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51421002, 51627803, 91733301, 51761145042, 21501183, 51402348, 53872321, and 11874402)the Knowledge Innovation Program and the Strategic Priority Research Program (Grant XDB 12010400) of the Chinese Academy of Sciences
文摘In CZTSSe solar cells,a simple sodium-incorporation post-treatment method toward solution-processed Cu2Zn Sn S4precursor films is presented in this work.An ultrathin NaCl film is deposited on Cu2Zn Sn S4precursor films by spin-coating NaCl solution.In subsequent selenization process,the introduction of Na Cl is found to be benefacial for the formation of Cu2-xSe,which can further facilitate the element transportation,leading to dense and smooth CZTSSe films with large grains and less impurity Cu2Sn(S,Se)3phase.SIMS depth profiles confirm the gradient distribution of the sodium element in Na-doped absorbers.Photoluminescence spectra show that the introduction of appropriate sodium into the absorber can inhibit the band tail states.As high as 11.18% of power conversion efficiency(PCE)is achieved for the device treated with 5 mg mL^-1 NaCl solution,and an average efficiency of Na-doped devices is 10.71%,13%higher than that of the control groups(9.45%).Besides,the depletion width and the charge recombination lifetime can also have regular variation with sodium treatment.This work offers an easy modification method for high-quality Na-doped CZTSSe films and high-performance devices,in the meantime,it can also help to further understand the effects of sodium in CZTSSe solar cells.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51627803,51402348,51421002,51372270,and 51372272)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘The Zn/Sn ratio in Cu2ZnSn（S, Se）4 （CZTSSe） films has been regulated to control the composition-related phase, defect, and photoelectric properties for high performance kesterite solar cells. It is found that the increase in the Zn/Sn ratio can slightly narrow the energy band gap to extend the light absorption range and improve the photocurrent. Optimal Zn/Sn ratio of 1.39 in CZTSSe film is obtained with the least secondary phase, the lowest defect density, and the longest charge recombination lifetime. Up to 10.1% photoelectric conversion efficiency has been achieved by this composition regulation.
文摘采用共溅射法结合后硒化成功制备出CZTSSe薄膜,主要研究了不同的硒化温度对CZTSSe薄膜与电池性能的影响。分别采用X射线衍射仪、拉曼光谱仪、扫描电子显微镜、紫外-可见-近红外分光光度计、霍尔效应测量仪及数字电源表对不同硒化温度下制备的CZTSSe薄膜的结构、形貌、光电与太阳电池性能进行了表征与分析。结果表明,当硒化温度为580℃时,CZTSSe薄膜的结晶性最好,薄膜表面均匀致密且其电阻率和载流子浓度达到最小值和最大值,分别为1.57Ω·cm和8.2×10^(17)cm^(-3),该硒化温度下制备得到的CZTSSe太阳电池的短路电流和转换效率最高达到30.68 m A/cm^2和5.17%。相对于550℃和600℃硒化温度下的CZTSSe太阳电池,其光电转换效率分别提高了36%和6%。另外,随着硒化温度的升高,CZTSSe薄膜在XRD中的(112)峰位和Raman中的A1模式振动峰位都向小衍射角和短波数方向移动,薄膜的禁带宽度也从1.26 e V减小至1.21 e V。
基金supported by the National Key R&D Program of China(2019YFB1503500,2018YFE0203400,2018YFB1500200)National Natural Science Foundation of China(U1902218,11774187),and 111 Project(B16027).
文摘VSe2 is with high electrical conductivity and high work function,thus it is beneficial for the carrier transport in the optoelectronic devices.However,the performance and mechanism of its effect on the photoelectronic devices conversion efficiency is still beyond understood.In this work,we fabricate VSe2 film between back contact and absorber layer Cu2ZnSn(S,Se)4(CZTSSe)film.We demonstrate that the VSe2 film in back contact region increases solar cell efficiency by 39%.Besides improving the carrier transport in the back contact region,the increasing can also be attributed to the reduction of the decomposition reaction of CZTSSe during the nucleation of CZTSSe as VSe2 fabricated between back contact and absorber layer.The present work not only provides an effective method to improve the performance of the optoelectronic device,but also shows an attractive application of metallic TMDs in optoelectronic device and solar cell energy generation.
文摘Cu2ZnSn（S,Se）4 （CZTSSe） is considered as the promising absorbing layer materials for solar cells due to its earth-abundant constituents and excellent semiconductor properties. Through solution-processing, such as various printing methods, the fabrication of high perfor- mance CZTSSe solar cell could be applied to mass production with extremely low manufacturing cost and high yield speed. To better fulfill this goal, environmentalfriendly inks/solutions are optimum for further reducing the capital investment on instrument, personnel and environmental safety. In this review, we summarized the recent development of CZTSSe thin films solar cells fabricated with benign solvents, such as water and ethanol. The disperse system can be classified to the true solution （consisting of molecules） and the colloidal suspension （consisting ofnanoparticles）.Three strategies for stabilization （i.e., physical method, chemical capping and self- stabilization） are proposed to prepare homogeneous and stable colloidal nanoinks. The one-pot self-stabilization method stands as an optimum route for preparing benign inks for its low impurity involvement and simple procedure. As-prepared CZTSSe inks would be deposited onto substrates to form thin films through spin-coating, spraying, electrodeposition or successive ionic layer adsorption and reaction （SILAR） method, followed by annealing in a chalcogen （S- or Se-containing） atmosphere to fabricate absorber. The efficiency of CZTSSe solar cell fabricated with benign solvents can also be enhanced by constituent adjustments, doping, surface treatments and blocking layers modifications, etc., and the deeper research will promise it a comparable performance to the non- benign CZTSSe systems.
