Guo Songhao, Li Yahui, Mao Yuhong, Tao Weijian, Bu Kejun, Fu Tonghuan, Zhao Chang, Luo Hui, Hu Qingyang, Zhu Haiming, Shi Enzheng, Yang Wenge, Dou Letian, Lü Xujie
Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai, China.
School of Engineering, Westlake University, Hangzhou, China.
Sci Adv. 2022 Nov 4;8(44):eadd1984. doi: 10.1126/sciadv.add1984. Epub 2022 Nov 2.
Two-dimensional (2D) semiconductor heterostructures are key building blocks for many electronic and optoelectronic devices. Reconfiguring the band-edge states and modulating their interplay with charge carriers at the interface in a continuous manner have long been sought yet are challenging. Here, using organic semiconductor-incorporated 2D halide perovskites as the model system, we realize the manipulation of band-edge states and charge distribution via mechanical-rather than chemical or thermal-regulation. Compression induces band-alignment switching and charge redistribution due to the different pressure responses of organic and inorganic building blocks, giving controllable emission properties of 2D perovskites. We propose and demonstrate a "pressure gating" strategy that enables the control of multiple emission states within a single material. We also reveal that band-alignment transition at the organic-inorganic interface is intrinsically not well resolved at room temperature owing to the thermally activated transfer and shuffling of band-edge carriers. This work provides important fundamental insights into the energetics and carrier dynamics of hybrid semiconductor heterostructures.
二维（2D）半导体异质结构是许多电子和光电器件的关键组成部分。长期以来，人们一直寻求以连续的方式重新配置带边态并调节它们与界面处电荷载流子的相互作用，但这具有挑战性。在这里，我们以包含有机半导体的二维卤化物钙钛矿为模型系统，通过机械调节而非化学或热调节实现了对带边态和电荷分布的操控。由于有机和无机结构单元的压力响应不同，压缩会导致能带排列切换和电荷重新分布，从而赋予二维钙钛矿可控的发光特性。我们提出并展示了一种“压力门控”策略，该策略能够在单一材料中控制多种发光状态。我们还揭示，由于带边载流子的热激活转移和重排，在室温下有机 - 无机界面处的能带排列转变本质上并未得到很好的解析。这项工作为混合半导体异质结构的能量学和载流子动力学提供了重要的基础见解。
