缓冲层对倒序铜锌锡硫薄膜太阳能电池性能的影响

Effect of Buffer Layer on the Performance of Superstrate Cu_2ZnSnS_4 Thin Film Solar Cell

为研究缓冲层材料的能带结构对倒序铜锌锡硫薄膜太阳能电池中吸收层和电子传输层之间的界面性能及光电转换效率的影响,制备了具有不同能带结构的CdS和ZnS缓冲层。通过紫外吸收光谱、X射线衍射、拉曼光谱、XPS能谱、电化学阻抗谱、强度调制光电流谱和光电流-电压曲线等的测试,对缓冲层和吸收层薄膜的能带结构、晶体结构、界面性能和光电性能进行了分析。结果表明,与ZnS作缓冲层相比,CdS作缓冲层时,缓冲层与铜锌锡硫吸收层形成的界面性能更好,有效促进了光生电子的界面转移和输运,减小了载流子的界面复合,从而显著提高了光电转换效率,最佳实验条件下提高了84.74%。

The CdS and ZnS buffer layers with different energy band structures were prepared to research their effects on the interfacial properties between the absorption layer and the electron transport layer and the photovoltaic conversion efficiency of the superstrate Cu2ZnSnS4 thin film solar cell.By the measurements of UV-Visible absorption spectrum,X-ray diffraction,Raman spectra,XPS spectroscopy,electrical impedance spectroscopy,intensity modulated photocurrent spectrum and photocurrent-voltage curves,the band structure of buffer layer and absorbing layer,crystal structure,interface properties and photoelectric performance are analyzed.Results show that interfacial properties of CdS buffer layer and Cu2ZnSnS4 layer are better than that of ZnS buffer layer,which can effectively promote the interface transfer and transport of photogenerated electrons and reduce the interfacial recombination of carriers,so that the photoelectric conversion efficiency of the superstrate Cu2ZnSnS4 film solar cell was increased by 84.74%.