CsPbX₃-based (X = I, Br, Cl) inorganic perovskite solar cells (PSCs) prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability. However, the high trap state density and serious charge recombination between low-temperature processed TiO₂ film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs. Here a thin polyethylene oxide (PEO) layer is employed to modify TiO₂ film to passivate traps and promote carrier collection. The impacts of PEO layer on microstructure and photoelectric characteristics of TiO₂ film and related devices are systematically studied. Characterization results suggest that PEO modification can reduce the surface roughness of TiO₂ film, decrease its average surface potential, and passivate trap states. At optimal conditions, the champion efficiency of CsPbI₂Br PSCs with PEO-modified TiO₂ (PEO-PSCs) has been improved to 11.24% from 9.03% of reference PSCs. Moreover, the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.

采用低温工艺制备的CsPbX ₃基（X=I、Br、Cl）无机钙钛矿太阳能电池（PSC）因其低成本和优异的热稳定性而备受关注。然而，低温处理的TiO ₂薄膜与无机钙钛矿层界面之间的高陷阱态密度和严重的电荷复合严重限制了全无机PSC的性能。这里采用薄的聚环氧乙烷（PEO）层来改性TiO ₂膜以钝化陷阱并促进载流子收集。系统研究了PEO层对TiO ₂薄膜及相关器件微观结构和光电特性的影响。表征结果表明，PEO改性可以降低TiO ₂薄膜的表面粗糙度，降低其平均表面电位，钝化陷阱态。在最佳条件下，带有 PEO 改性 TiO _{2的 CsPbI 2} Br PSC (PEO-PSC)的冠军效率已从参考 PSC 的 9.03% 提高到 11.24%。此外，PEO-PSC 中的滞后行为和电荷重组已被抑制。