采用N, N′-二正辛烷基-3, 4, 9, 10-苝四甲酰二亚胺(PTCDI-C8)对钙钛矿电池电子传输层(PCBM)进行界面修饰以减少PCBM与Al电极之间的漏电流, 提高阴极的电子收集效率。通过调节PTCDI-C8薄膜的厚度优化界面接触和电子传输性能。实验结果表明: 当PTCDI-C8薄膜的厚度为20 nm时得到的器件性能最优。光电转换效率(PCE)由5.26%提高到了8.65%, 开路电压(Voc)为0.92 V, 短路电流(Jsc)为15.68 mA/cm2, 填充因子(FF)为60%。PTCDI-C8能够有效阻挡空穴向阴极传输, 同时PTCDI-C8具有较高的电子迁移率以及较高的稳定性, 在增加电子传输的同时, 可减少环境对PCBM的侵蚀, 提高了器件的稳定性。

N, N′-di-n-octyl-3,4,9,10-perylene tetracarboxylic diimide(PTCDI-C8) was used as the interfacial layer of the electron transport layer PCBM to reduce the leakage current between PCBM and Al electrode and to improve the electron collecting efficiency of cathode. By adjusting the thickness of PTCDI-C8 film, the interfacial contact and electron transport properties were optimized. Compared with the control devices, the power conversion efficiency (PCE) of the optimal device achieves 8.65% with 20 nm thickness PTCDI-C8 film, with an open circuit voltage (Voc) of 0.92 V, a short circuit current (Jsc) of 15.68 mA/cm2 and a fill factor (FF) of 60%. PTCDI-C8 layer can effectively block the hole transmitting to the cathode. With a higher electron mobility and stability, PTCDI-C8 layer can reduce the environment erosion on the PCBM. In summary, the introduction of PTCDI-C8 film as cathode buffer layer improves the performance and stability of the device.