Subsurface Characteristics of Metal-Halide Perovskites Polished by an Argon Ion Beam
Subsurface Characteristics of Metal-Halide Perovskites Polished by an Argon Ion Beam
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DOI：
10.1021/acs.jpcc.2c09122
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发表时间：
2023-04-10
影响因子：
3.7
通讯作者：
Yoon，Heayoung P.
中科院分区：
文献类型：
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作者：
Hsu，Yu-Lin;Li，Chongwen;Yoon，Heayoung P.
聚焦离子束（FIB）技术已被频繁地用于对金属卤化物钙钛矿进行切片以用于微结构研究。然而，离子束直接照射样品表面可能会改变其性质远不同于原始的，可能导致修改老化应力下的劣化机制。在这里，我们结合联合收割机互补的方法来测量抛光钙钛矿的表面下的特性，并确定负责测量性能的化学物质。结合Monte Carlo模拟的实验结果分析表明，通过掠射角Ar+束照射（4 kV，3°），在甲基碘化铅铵（MAPbI 3）的次表面的第一个15 nm处发生原子位移和局部加热。富铅、缺碘的表面促进热老化条件下的快速相分离。另一方面，尽管表面改性，我们的实验证实，其余的MAPbI3散装保持材料的完整性。我们的观察支持抛光钙钛矿可以用于研究远离蚀变地下的大块或掩埋结的性质。
Focused ion beam (FIB) techniques have been frequently used to section metal-halide perovskites for microstructural investigations. However, the ion beams directly irradiating the sample surface may alter its properties far different from those of pristine, potentially leading to modified deterioration mechanisms under aging stressors. Here, we combine complementary approaches to measure the subsurface characteristics of polished perovskites and identify the chemical species responsible for the measured properties. Analysis of the experimental results in conjunction with Monte Carlo simulations indicates that atomic displacements and local heating occur in the first ≈15 nm of the subsurface of methylammonium lead iodide (MAPbI3) by glancing-angle Ar+beam irradiation (4 kV at 3°). The lead-rich, iodine-deficient surface promotes rapid phase segregation under thermal aging conditions. On the other hand, despite the subsurface modification, our experiments confirm that the rest of the MAPbI3bulk retains the material integrity. Our observation supports that polished perovskites could serve in studying the properties of bulk or buried junctions far away from the altered subsurface with care.