分别制备了以苯甲酸锂、碳酸铯和聚氧化乙烯为阴极修饰层的基于P3HT∶PCBM体系的本体异质结有机光伏电池。比较了3种阴极修饰层对器件性能及稳定性的影响。结果表明:选择合适的阴极修饰层材料是提高光电转换效率、延长电池使用寿命的可行性途径之一。纯无机阴极修饰层不能有效地阻挡氧气和水进入活性层,对于减缓器件的性能衰退效果不如有机阴极修饰层材料。有机聚合物材料可以减小漏电流的产生,开路电压和填充因子都得到很大提高,有利于提高器件的性能及稳定性。合成可溶液加工的具有极性基团的共轭聚合物材料是未来阴极修饰层的发展方向。
Enhanced performance and stability of polymer solar cells based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene -phenyl-C61 butyric acid methyl ester(PCBM) blend were obtained by using cesium carbonate(Cs2CO3),lithium benzoate(C6H5COOLi),poly(ethylene-oxide)(PEO) as cathode buffer layer.The improved performance may attribute to the cathode buffer layer which reduces the interface resistance between the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportation.In addition,the cathode buffer layer may serve as an effective oxygen and moisture diffusion barrier for the organic solar cells.The organic cathode buffer layer is superior to the inorganic materials.Solution processed conjugated polymer bearing strong polar groups in the side chains is a promising candidate as an interlayer to improve the efficiency of electron collection and to reduce the ambience influence on the stability of polymer solar cells.