Mixed-cation perovskite solar cells have attracted tremendous attention in space applications due to their excellent power conversion efficiency (PCE) and stability to light and heat. Although the evolution of photovoltaic performance in different space environments has been investigated, the role of inorganic cesium ions (Cs⁺) in the enhancement of irradiation resistance needs to be further clarified. Herein, the structure and performance evolution of Cs-doped CH₃NH₃PbI₃ (MAPbI₃) films and planar heterojunction devices under proton irradiation up to 1 × 10¹⁶ p cm⁻² were studied. 5% of Cs⁺ doping can increase the cohesive energy of MAPbI₃ and effectively alleviate the lattice strain induced by proton irradiation, thereby enhancing the crystallinity and stability of films. The bandgap changes of irradiated Cs_0.05MA_0.95PbI₃ films under the identical fluence were only one third of that of MAPbI₃ films. Upon irradiation under the fluence of 1 × 10¹⁴ p cm⁻², the density of trap states in the undoped and 5%Cs-doped films increased by 71% and 9%, respectively, and the average PCE of 20 corresponding devices decreased only by 12% and 9%, respectively. This proves that the replacement of organic methylamine ion with inorganic cesium ion contributes to the improvement of MAPbI₃ resistance to proton irradiation, thus confirming the application prospects of mixed-cation or all-inorganic perovskite solar cells in spacecraft.

混合阳离子钙钛矿太阳能电池由于其优异的功率转换效率（PCE）和对光和热的稳定性而在空间应用中引起了极大的关注。尽管已经研究了不同空间环境下光伏性能的演变，但无机铯离子（Cs ⁺）在增强抗辐照性中的作用需要进一步阐明。在此，研究了Cs掺杂的CH ₃ NH ₃ PbI ₃ (MAPbI ₃ )薄膜和平面异质结器件在高达1×10 ¹⁶ p cm ^-2的质子辐照下的结构和性能演变。5% Cs ⁺掺杂可以提高MAPbI ₃的内聚能，有效缓解质子辐照引起的晶格应变，从而提高薄膜的结晶度和稳定性。辐照后的Cs _0.05 MA _0.95 PbI _{3薄膜在相同能量密度下的带隙变化仅为MAPbI 3}薄膜的三分之一。在 1 × 10 ¹⁴ p cm ^{-2的通量下照射}，未掺杂和 5% Cs 掺杂薄膜中的陷阱态密度分别增加了 71% 和 9%，而 20 个相应器件的平均 PCE 分别仅下降了 12% 和 9%。这证明用无机铯离子替代有机甲胺离子有助于提高MAPbI ₃对质子辐照的耐受性，从而证实了混合阳离子或全无机钙钛矿太阳能电池在航天器中的应用前景。