Yue Man, Su Jie, Zhao Peng, Lin Zhenhua, Zhang Jincheng, Chang Jingjing, Hao Yue
State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, Shaanxi Joint Key Laboratory of Graphene, School of Microelectronics, Xidian University, 2 South Taibai Road, Xi'an, 710071, People's Republic of China.
Nanomicro Lett. 2019 Oct 18;11(1):91. doi: 10.1007/s40820-019-0320-y.
Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells (PSCs). Here, doping engineering of a ZnO electron transport layer (ETL) and CsPbI/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI-based PSCs. The results show that when introducing a TiO buffer layer while increasing the ZnO layer doping concentration, the open-circuit voltage, power conversion efficiency, and fill factor of the CsPbI-based PSCs can be improved to 1.31 V, 21.06%, and 74.07%, respectively, which are superior to those of PSCs only modified by the TiO buffer layer or high-concentration doping of ZnO layer. On the one hand, the buffer layer relieves the band bending and structural disorder of CsPbI. On the other hand, the increased doping concentration of the ZnO layer improves the conductivity of the TiO/ZnO bilayer ETL because of the strong interaction between the TiO and ZnO layers. However, such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface. These results provide a comprehensive understanding of the CsPbI/ZnO interface and suggest a guideline to design high-performance PSCs.
界面工程被认为是优化钙钛矿太阳能电池（PSC）性能的一种有效且无创的手段。在此，通过引入界面层对ZnO电子传输层（ETL）进行掺杂工程以及CsPbI/ZnO界面工程，以提高基于CsPbI的PSC的性能。结果表明，在增加ZnO层掺杂浓度的同时引入TiO缓冲层时，基于CsPbI的PSC的开路电压、功率转换效率和填充因子可分别提高到1.31 V、21.06%和74.07%，优于仅通过TiO缓冲层修饰或ZnO层高浓度掺杂的PSC。一方面，缓冲层缓解了CsPbI的能带弯曲和结构无序。另一方面，由于TiO和ZnO层之间的强相互作用，ZnO层掺杂浓度的增加提高了TiO/ZnO双层ETL的导电性。然而，对于PCBM/ZnO双层ETL则未观察到这种现象，因为PCBM/ZnO界面的层间相互作用较弱。这些结果为CsPbI/ZnO界面提供了全面的理解，并为设计高性能PSC提供了指导方针。
