四方晶系
拉曼光谱
热稳定性
晶格常数
氮化硼
材料科学
化学物理
电介质
钙钛矿(结构)
碘化物
亚稳态
相变
化学
晶体结构
化学工程
纳米技术
结晶学
衍射
凝聚态物理
光电子学
光学
无机化学
物理
有机化学
工程类
作者
P.S. Peercy,G.A. Samara,B. Morosin
标识
DOI:10.1016/0038-1098(75)90365-8
摘要
The methylammonium lead iodide (MAPbI3) perovskite has attracted considerable interest for its high-efficiency, low-cost solar cells, but is currently plagued by its poor environmental and thermal stability. To aid the development of robust devices, we investigate here the microscopic degradation pathways of MAPbI3 microplates. Using in situ transmission electron microscopy to follow the thermal degradation process, we find that under moderate heating at 85°C the crystalline structure shows a gradual evolution from tetragonal MAPbI3 to trigonal lead iodide layered crystals with a fixed crystallographic direction. Our solid-state nudged elastic band calculations confirm that the surface-initiated layer-by-layer degradation path exhibits the lowest energy barrier for crystal transition. We further show experimentally and theoretically that encapsulation of the perovskites with boron nitride flakes suppresses the surface degradation, greatly improving its thermal stability. These studies provide mechanistic insight into the thermal stability of perovskites that suggests new designs for improved stability.
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