Inhibition of PbI2-induced defects by doping MABr for high-performance perovskite solar cells

The performance of FAPbI(3)-based perovskite solar cells (PSCs) has been drastically improved with a photoelectric conversion efficiency (PCE) of 25.7%, showing attractive application potential. To achieve higher efficiency and longer-term stability of PSCs, a large number of passivation methods are used to inhibit Pb and I defects of FAPbI(3) films. In this study, we developed a facile method to suppress the residual PbI2 of perovskite films and the related defects efficiently by a two-step spin-coating process, which prominently improves the carrier lifetime of alpha-FAPbI(3) films (from 459 ns to 1346 ns). In addition, the morphology and crystallization characteristics of the films were also significantly improved, and the grains grew up to 1 mu m. The efficiency of FAPbI(3)-based PSCs fabricated by this method reached 22.64%.

Automated summary

A facile method was developed in this study to efficiently suppress the residual PbI2 and related defects in perovskite films by a two-step spin-coating process, significantly improving the carrier lifetime and grain growth of the alpha-FAPbI(3) films, and further enhancing the performance of perovskite solar cells.