Low‐temperature α‐phase stabilization using HI or zwitterions in cesium lead iodide (CsPbI₃) endures the metastable phase properties but is thermally unstable. Doping with a small amount of heterovalent metals (i.e., Bi³⁺, Sb³⁺) in CsPbI₃ has been assumed to stabilize the α‐phase, while here this assumption is challenged. It is demonstrated that heterovalent metal ion doping stabilizes β‐CsPbI₃ at low temperatures without replacing the Pb²⁺ cations, while divalent cations (i.e., Ba²⁺, Sr²⁺, and Sn²⁺) doping stabilizes the α‐CsPbI₃ by replacing the Pb²⁺ cations. This finding is demonstrated by both theoretical and experimental results. It is also found that the divalent cations stabilize α‐CsPbI₃ films, making thermally stable at high temperatures, whereas heterovalent metal‐doping stabilizes β‐CsPbI₃ films, making metastable. The doping influence on crystal grains and the chemical composition of thin films is discussed. In particular, the charge dissociation kinetics for the Sr doped thin film are much enhanced than α‐CsPbI₃ and Ba doped thin films, also the initial results of the fabricated perovskite red‐light‐emmiting diode suggests that the Sr‐doped thin films would be more suitable for the device fabrication. These findings will guide a way for further development in thermally and air‐stable optoelectronic devices.

中文翻译：

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揭示金属掺杂对CsPbI3钙钛矿性能的影响

使用碘化铯碘化铅（CsPbI ₃）中的HI或两性离子进行的低温α相稳定处理虽然具有亚稳态的相性质，但具有热稳定性。假设在CsPbI _3中掺杂少量的杂价金属（即Bi ³⁺，Sb ³⁺）可稳定α相，但在此挑战了这一假设。据证实heterovalent金属离子掺杂企稳β-CsPbI ₃在低温下，无需更换的Pb ²⁺阳离子，而二价阳离子（即，钡²⁺，锶²⁺和Sn ²⁺）掺杂稳定α-CsPbI ₃通过替换Pb ²⁺阳离子。理论和实验结果都证明了这一发现。还发现的是，二价阳离子稳定α-CsPbI _3层膜，在高温下使热稳定的，而heterovalent金属掺杂稳定β-CsPbI _3层膜，使亚稳。讨论了掺杂对晶粒和薄膜化学成分的影响。特别地，对于Sr的电荷解离动力学掺杂薄膜比在多增强α-CsPbI ₃掺杂钡的薄膜，以及制成的钙钛矿红色发光二极管的初步结果也表明，掺锶的薄膜将更适合于器件的制造。这些发现将为热和空气稳定的光电器件的进一步开发提供指导。