钙钛矿有机-无机杂化卤化铅微结构相关的激子和缺陷态物理问题研究

In the past few years, the application of perovskite hybrid lead halides (e.g. CH3NH3PbI3) for photovoltaics, light emitting and detecting has achieved great successes, which has attracted considerable interest from the field of physics, chemistry and material. Recently, it has been shown that the exciton and trap states could play significant roles in determining the optical and electrical properties of the perovskite material. This material also provides an opportunity for the studying and application of the exciton physics. Regulating these electronic states is the key to obtain higher performed materials and devices while deeply understanding their physics properties and related mechanisms are the basis. Therefore, to understand and solve the urgent stability problems and to explore the physics properties and potential application of the exciton, here we propose to study the microstructure-dependent exciton and trap properties of the hybrid lead halide perovskite material. We will identify the fine electronic structure of the band-edge and trap states, the charge transfer processes and the exciton-induced stimulated emission of the perovskite material. The correlation between these states and the microstructure of the material will also be revealed. This study will help establish a foundation for the understanding and regulating the novel optoelectronic behaviors of these materials, and will give guides to construct higher-performed devices through the microstructure and electronic energy state regulations.

近年来，以甲胺铅碘(CH3NH3PbI3)为代表的钙钛矿有机-无机杂化卤化铅材料在光伏、发光和探测等领域的应用取得了巨大进展，吸引了物理、化学和材料等诸多领域的兴趣。初步研究表明，激子和缺陷态对该类材料的光学和电学行为具有重要影响。如何调控这些电子能态是获得高性能材料和器件的关键，而认识它们的基本物理性质和相关的物理机制则是基础。故，为了进一步认识和解决杂化卤化铅钙钛矿材料面临的物理稳定性问题，并探索其激子的物理特性和潜在应用，本项目拟开展钙钛矿有机-无机杂化卤化铅材料微结构相关的激子和缺陷态物理问题研究。我们将研究该类材料的带边和缺陷态能级精细结构、电荷转移动力学过程和激子相关的受激辐射行为，以及与材料微结构间的物理关联，探索结构与性质间的一般规律和相关物理机制。这将为认识和调控该类材料的新奇光电物理行为建立基础，也会为通过微结构和能态调控实现更高性能光电器件的构建提供理论指导。

近年来，以甲胺铅碘(CH3NH3PbI3)为代表的钙钛矿有机-无机杂化卤化铅材料在光伏、发光和探测等领域的应用取得了巨大进展，吸引了物理、化学和材料等诸多领域的兴趣。激子和缺陷态对该类材料的光学和电学行为具有重要影响。如何调控这些电子能态是获得高性能材料和器件的关键，而认识它们的基本物理性质和相关的物理机制则是基础。为了进一步认识和解决杂化卤化铅钙钛矿材料面临的物理稳定性问题，并探索其激子的物理特性和潜在应用，本项目开展了钙钛矿有机-无机杂化卤化铅材料微结构相关的激子和缺陷态物理问题研究。我们研究了该类材料的带边和缺陷态能级精细结构、电荷转移动力学过程和激子相关的受激辐射行为，以及与材料微结构间的物理关联。我们在甲胺铅溴材料中发现了自由载流子、自由激子和束缚激子能级，并建立了束缚态激子与深缺陷的关联。进一步通过材料晶格有序度调控稳定了室温激子态，实现了低阈值高增益激子受激辐射。这为认识和调控该类材料的新奇光电物理行为建立了基础，也为通过微结构和能态调控实现更高性能光电器件的构建提供理论指导。