高压下低维材料的光学特性调控

压力作为独立于物质温度和组分的热力学参量,为物质科学的研究和创新提供了新的维度,已成为发展新概念、创造新理论及探索新材料的重要源泉。本文主要概述了作者近年来在高压下低维材料的光学特性调控方面所取得的一些进展。通过压力改变激子结合能和卤素八面体的扭曲行为,实现了低维卤化物钙钛矿纳米材料发光从“0”到“1”的突破,提出了压力诱导发光的概念;通过引入压力效应,利用压力对纳米材料表面配体的调控,改变了表面配体与CdSe量子点的相互作用和能级耦合,促进了Hirshfeld电荷转移,从而实现了CdSe量子点的荧光大幅度增强近一个数量级;借助高压手段调控能带结构,成功实现了CdSe/CdS半导体纳米晶由准Ⅱ型核壳结构向Ⅰ型核壳结构的构型转变。上述工作加深了对发光材料在极端压缩条件下构效关系的深入理解和认识,研究成果为设计和制备具有特定功能的低维材料提供了新方法。

Optical Tuning of Low-Dimensional Materials under High Pressure

As a thermodynamic parameter,independent of temperature and composition,pressure provides a new dimension for material science research and innovation.Pressure has become an important source for developing new concepts,creating new theories and exploring new materials.Here,some advances in optical properties regulation of low-dimensional materials under high pressure are summarized.By changing the exciton binding energy and the distortion behavior of halide octahedra under pressure,the luminescence of low-dimensional halide perovskites experienced a stark change from"0"to"1".Meanwhile,we innovatively put forward the new concept of"pressure-induced emission(PIE)".Through introducing the pressure effect,it is able to regulate the surface ligands of nanomaterials,change the interaction and energy level coupling between the surface ligands and CdSe quantum dots.This will promote the Hirshfeld charge transfer,thus realizing the significant emission enhancement of CdSe quantum dots by nearly one order of magnitude.With the help of high-pressure regulation on energy band structure,we successfully achieved the core/shell configuration transition of CdSe/CdS semiconductor nanocrystals from quasi-type Ⅱ to type Ⅰ core-shell structure.The above work will deepen the understanding of the structure-property relationship of luminescent materials under extreme compression conditions.The research results provide new methods for the design and preparation of low-dimensional materials with specific functionality.