All-inorganic perovskite solar cells (PSCs) attract attention due to their excellent optical properties and high thermal stability, but energy loss is a challenge due to the trap-assisted recombination loss at the imperfect film morphology. We herein demonstrate the optimization of α-CsPbI₂Br morphology including low defect density and large grain size by employing cesium chloride (CsCl) as an additive. High-quality CsPbI₂Br film grown with CsCl reveals high crystallinity and largely-grained morphology, which provides reduced defect density and energy loss. As a result, we optimize the CsPbI₂Br device with 1% CsCl additive, which shows a power conversion efficiency (PCE) of 11.04% with an open-circuit voltage (V_OC) of 1.33 V. The CsPbI₂Br with CsCl shows stability maintaining >80% of the initial efficiency being aged for >360 h in ambient atmosphere. The CsCl-employed device also retains 98% of initial PCE after being heated at 85 °C for 12 h, verifying enhanced stability of the all-inorganic PSCs. In addition, the photovoltaic performance under white light-emitting diode yields PCE over 25% with a high V _OC of 1.08 V in the presence of CsCl, which realizes the stable all-inorganic PSCs applicable in outdoor/indoor environments.

全无机钙钛矿太阳能电池（PSC）因其优异的光学性能和高热稳定性而备受关注，但由于不完美的薄膜形态下的陷阱辅助复合损失，能量损失是一个挑战。我们在此展示了通过使用氯化铯 (CsCl) 作为添加剂优化 α-CsPbI ₂ Br 形态，包括低缺陷密度和大晶粒尺寸。用 CsCl 生长的高质量 CsPbI ₂ Br 薄膜显示出高结晶度和大颗粒形态，从而降低了缺陷密度和能量损失。因此，我们使用 1% CsCl 添加剂优化了 CsPbI ₂ Br 器件，在开路电压 ( V _OC) 的 1.33 V。CsPbI ₂ Br 与 CsCl 显示出稳定性，在环境大气中老化 >360 小时后仍能保持初始效率的 80% 以上。在 85°C 下加热 12 小时后，使用 CsCl 的装置还保留了 98% 的初始 PCE，验证了全无机 PSC 的稳定性增强。此外，在CsCl 存在下，白光发光二极管下的光伏性能产生超过 25% 的 PCE，V _OC高达 1.08 V，实现了稳定的全无机 PSCs 适用于室外/室内环境。