Carrier lifetime enhancement in halide perovskite via remote epitaxy
Carrier lifetime enhancement in halide perovskite via remote epitaxy
复制标题
通过远程外延提高卤化物钙钛矿的载流子寿命
DOI：
10.1038/s41467-019-12056-1
复制
发表时间：
2019-09-12
影响因子：
16.6
通讯作者：
Shi, Jian
中科院分区：
文献类型：
--
作者：
Jiang, Jie;Sun, Xin;Shi, Jian
晶体位错是导致传统半导体器件中载流子动力学不佳的主要原因之一。卤化物钙钛矿在光电子器件中具有广阔的应用前景。然而，位错如何影响其载流子动力学在“缺陷容忍”卤化物钙钛矿在很大程度上是未知的。在这里，通过使用涂覆有石墨烯的极性衬底的远程外延方法，我们合成了具有受控位错密度的外延卤化物钙钛矿。第一性原理计算和分子动力学模拟分别揭示了远程外延中弱的薄膜-衬底相互作用和低密度位错机制。高分辨率透射电子显微镜、高分辨率原子力显微镜和Cs校正扫描透射电子显微镜揭示了远程外延膜的晶格/原子和位错结构。通过对位错密度的控制，揭示了卤化物钙钛矿中位错-载流子的动力学关系。该研究为开发具有低位错密度和改善载流子动力学的自支撑卤化物钙钛矿薄膜提供了一种途径。
Crystallographic dislocation has been well-known to be one of the major causes responsible for the unfavorable carrier dynamics in conventional semiconductor devices. Halide perovskite has exhibited promising applications in optoelectronic devices. However, how dislocation impacts its carrier dynamics in the ‘defects-tolerant’ halide perovskite is largely unknown. Here, via a remote epitaxy approach using polar substrates coated with graphene, we synthesize epitaxial halide perovskite with controlled dislocation density. First-principle calculations and molecular-dynamics simulations reveal weak film-substrate interaction and low density dislocation mechanism in remote epitaxy, respectively. High-resolution transmission electron microscopy, high-resolution atomic force microscopy and Cs-corrected scanning transmission electron microscopy unveil the lattice/atomic and dislocation structure of the remote epitaxial film. The controlling of dislocation density enables the unveiling of the dislocation-carrier dynamic relation in halide perovskite. The study provides an avenue to develop free-standing halide perovskite film with low dislocation density and improved carried dynamics.