多元金属氧化物纳米晶的液相激光烧蚀普适可控生长及紫外光响应研究

Due to their wide band gap, the multicomponent metal oxides are typically used for ultraviolet/deep ultraviolet detections. By adjusting their component ratio and phase, the electronic structure and band gap can be effectively tuned to be adapted to different wavelengths. In this proposal, we propose to thoroughly study the controllable preparation, growth mechanism and tuning of electronic structure of multicomponent metal oxide nanocrystals via a combination of LAL and solvothermal methods. Combining these two methods, the growth and microstructure of multicomponent metal oxide nanocrystals, as well as their dependence on the preparation conditions will be investigated in detail in order to reveal their growth mechanism in complex reaction environment and develop a universal method to prepare multicomponent metal oxide nanocrystals. The influences of component, phase and microstructure on the electronic structure and optoelectronic properties of the prepared multicomponent metal oxide nanocrystals will be studied, and the tuning mechanism of electronic structure and band gap of multicomponent metal oxides will also be clarified. We would also investigate the fabrication and performance of ultraviolet photodetectors based on the prepared multicomponent metal oxide nanocrystals. The photoresistor and heterojunction ultraviolet photodetectors will be fabricated to explore how the component ratio, phase, microstructure and device configuration would affect the performances (such as gain, responsibility, quantum efficiency and response times) of the photodetectors. The correlation between the microstructure and key performance parameters of photodetector will be elucidated. This project will be able to expedite the development of new types of ultraviolet photodetectors.

宽禁带多元金属氧化物易通过控制组元比和相结构来调控其电子结构和光学带隙，可用于紫外/深紫外光探测。本项目拟结合液相激光烧蚀（LAL）和溶剂热方法，深入开展多元金属氧化物纳米晶可控制备、生长机理、电子结构调控、紫外光探测器构筑与性能的研究。研究多元金属氧化物纳米晶的生长和微结构对制备条件的依赖及其生长规律，揭示复杂反应环境中多元金属氧化物纳米晶的生长机理，发展多元金属氧化物纳米晶的LAL与溶剂热反应相结合的普适制备方法。研究多元金属氧化纳米晶的组成、相结构及微结构对其电子结构和光电性能的影响,阐明多元金属氧化物纳米晶电子结构与能带调控机制。构筑多元金属氧化物纳米晶组装膜紫外光探测器，研究纳米晶组装膜的光照依赖电输运特性，研究纳米晶组成、相结构、微结构和器件构型对紫外光探测器性能的影响，建立纳米晶微结构与探测器关键性能参数的内在关联。本项目的开展将推动新型紫外/深紫外光电探测器的发展。

本项目以高性能日盲紫外光探测为牵引，针对项目提出的关键科学问题，围绕项目研究内容，深入开展了紫外光响应半导体纳米晶的液相激光烧蚀（LAL）微观过程与可控生长、微结构调控、生长机理、电子结构及紫外光探测器构筑与光探测性能的研究。搭建了原位瞬态观察实验装置及双光束激光LAL制备系统，发展了LAL空泡及冲击波动力学“激光束偏转-延时成像”原位研究方法，观察到LAL双空泡耦合增强、微纳米颗粒LAL微空泡等新颖效应。发展了LAL-溶剂热法、“双光束LAL”合金化方法，及紫外光响应宽带隙材料普适合成技术，制备了高结晶性、高纯度的Zn2SnO4纳米晶，通过晶面选择性生长获得了由{111}和{100}晶面组成的高结晶性镓酸锌截顶八面体微晶，实现了其相结构和电子结构的调控及从3.2 eV到4.5 eV深紫外区的带隙拓展，阐明了其生长机理。发展了紫外光探测器性能提升策略，构筑了LAL双金属氧化物锡酸锌纳米晶紫外光探测器，实现了响应速度达0.2ms的超快光响应和103高开关比。通过减少陷阱加快输运，提升了深紫外极弱光探测能力，研制出可用于极弱光高灵敏、高开关比探测的镓酸锌深紫外光探测器，探测限达21.8 nW/cm2，探测度超过4×1014 Jones，实现了目标深紫外光的探测成像识别。通过材料界面优化、器件能级匹配和表面等离子体近场增强，实现了氧化锌基光探测器器件功能层的“软”接触、精准的能级匹配，促进了光生载流子的分离和输运，提升了氧化锌基纤维状紫外光探测器性能，并构筑了氧化锌基纤维状织物探测器。项目研究获得了一批知识产权和前沿创新成果，为发展高性能紫外/深紫外光电器件提供了关键材料和技术基础。