通过将聚乙二醇(PEG)掺入活性层制备聚合物太阳能电池,利用PEG的迁移特性获得阴极修饰层,研究PEG阴极修饰层对聚合物太阳能电池光电性能的影响。X射线光电子能谱(XPS)分析表明,掺入活性层中的PEG迁移到活性层与Al电极之间,形成了阴极缓冲层。吸收光谱、电流密度-电压特性曲线和外量子效率谱的分析表明,PEG阴极缓冲层的形成改善了活性层与阴极的界面接触特性,降低了活性层与电极之间的能级势垒,有利于载流子传输,因此显著地改善了聚合物太阳能电池的光电性能,使得器件的开路电压Voc、短路电流密度Jsc和填充因子(FF)都有明显提高。当P3HT:PCBM活性层中掺入体积比为0.5%的PEG时,聚合物太阳能电池的能量转换效率(PCE)最高,达到了3.07%,比未掺杂PEG的参考器件提高了38.5%。
Polymer solar cells with polyethylene glycol (PEG) cathode buffer layer formed by PEG migra- tion were prepared,and the photoelectric performance of polymer solar cells was studied in this paper. The X-ray photoelectron spectroscopy (XPS) results indicate that PEG migrates from active layer to the interface between the active layer and A1 electrode and forms a cathode buffer layer. The results of ultra-violet-visible absorption spectra, current density-voltage (J-V) characteristic curves and external quantum efficiency spectra show that the formed PEG buffer layer improves the interfacial contact and reduces the energy barrier between active layer and electrode, thus improves the photoelectric performance of the polymer solar cell significantly, and the short circuit current density (Jsc), open circuit voltage (Voc) and fill factor (FF) are all enhanced obviously. The polymer solar cell with 0. 5% (volume per-centage) PEG doped into P3HT: PCBM active layer gives the maximum power conversion efficiency (PCE) of 3.07% ,which is enhanced by 38. 5% compared with the device without PEG.