Strain manipulation for Halide Perovskite Performance Improvements

金属-有机杂化卤化物钙钛矿代表了一类新的材料，可能会对一系列光电子应用产生巨大影响，但与硅和III-V材料的历史类似，为了实现这些雄心勃勃的目标，需要彻底了解它们的材料性质。由于其杂化性质，钙钛矿在结构上是灵活的，可以在多个长度尺度上以低能源成本获得各种晶体构型。局部晶相、多型位错或各种类型的位错是在这些材料中可能导致本征应变场的一些晶体组态。如何利用这一点来改进性能还没有得到彻底和系统的探索。该项目的目标是识别纳米尺度的本征应变场的来源，实现其在外部应力源下的完全操纵，并利用它来控制光电特性，以展示性能的改进。这将通过建立一种独特的相关光学和X射线同步加速器显微镜方法来实现，该方法由候选人在同步加速器表征方面的丰富经验培养而成，并得到主办方在多模式光学显微镜方面的卓越支持。

Metal-organic hybrid halide perovskites represent a new class of materials that could have an enormous impact across a range of optoelectronic applications, but, similar to the history of silicon and III-V materials, a thorough understanding of their material properties is required to achieve these ambitious aims. As a result of their hybrid nature, perovskites are structurally flexible with various crystallographic configurations accessible at low energy cost at multiple length scales. Local crystalographic phases, polytypes or various classes of dislocations are some of the crystalographic configurations that can result in intrinsic strain fields in these materials. How this can be exploited for performance improvements has yet not been thoroughly and systematically explored. The objective of this project is to identify the sources of intrinsic strain fields at the nanoscale, achieve their full manipulation with external stressors and utilise it to control optoelectronic properties for demonstrating performance improvements. This will be achieved by establishing a unique correlative optical and X-ray synchrotron microscopy approach fostered by the candidate's extensive experience with synchrotron characterisation and backed by excellence in multimodal optical microscopy of the host group.