基于金属纳米粒子 / II-VI族低维半导体复合纳米结构的紫外光探测器的性能调控与机理研究

The proposed project aims to the synthesis of low-dimensional Group II-VI semiconductors (mainly focused on ZnS，ZnO，ZnTe，CdTe and CdS) nanostructures and their heterostructures/hierarchical nanostructures (mainly focused on ZnS/ZnO、ZnS/ZnSe and ZnS/CdS), the growth of which will be controlled and then based on for subsequent research, and combined with various metal nanoparticles (mainly focused on Au、Ag and Pt) with controlled sizes, shapes, and array density. It involves observing the morphologies and spectral characteristics of the fabricated nanostructures, and further on, qualitatively investigating the inherent relationships of performances and morphologies of the photoelectric devices, which are produced based on these particular types of nanostructures. The research work will be specifically set to develop an efficient and reliable way to construct the high performances ultraviolet (UV) photodetectors based on metal nanoparticles- Group II-VI semiconductor nanocomposites. And, consequently, the physical mechanism of the caused performances, relating to photoelectric devices and functional surfaces, can be expounded. Surface functionalization, in accordance with the particular material involved, will be developed, which complies with the ultimate aim of accomplishing high-performance heterogeneous composites. Through the research work of this project, it is expected that the investigation and interpretation of microscopic mechanism and morphological development of the nanocomposite shall be achieved. The concerned fields include multi-functionalization of the surfaces of photoelectric devices and systematic research of "synthesis-performance-application", which will provide references in material processing and theoretical analysis for the advancement of new-generation nanodevices.

本研究拟在控制生长II-VI族低维半导体（ZnS，ZnO，ZnTe，CdTe和CdS为主）纳米结构及其异质/分级结构（ZnS/ZnO、ZnS/ZnSe和ZnS/CdS等）的基础上，发展有效普适方法，复合不同大小、不同形状、不同阵列密度的多种金属纳米粒子（Au、Ag 和Pt），探索简单适用的构筑方法/技术（如界面自组装等构筑技术），构筑复合纳米结构的紫外光探测器，深入研究其光电器件性能和结构形貌、微结构等的相互内在构效关系，阐明内在物理机制，实现紫外光探测器制备的低成本、高性能和多功能化。本项目通过低维纳米结构的控制生长、复合结构设计、内在物理机制与性能研究，揭示该纳米制造工艺的物理机制及其调控规律，对低维纳米结构的应用研究有重要意义，为下一代纳米器件的研制提供科学依据，奠定理论和实验基础。

该项目紧紧围绕课题研究的总目标，在基于金属纳米粒子 / II-VI族低维半导体复合纳米结构的紫外光探测器的性能调控与机理研究上，开展了较为深入和系统的研究工作，如通过构建异质结以及Au纳米颗粒的热电子效应改善探测器光电性能的方法成功有效并拓展到其他体系：利用旋涂法将水热制得的CdMoO4微米片涂布在ZnO纳米颗粒膜表面后，将CdMoO4-ZnO复合膜组装成异质结探测器。CdMoO4微米片的负载量经优化的复合膜异质结探测器相较ZnO膜探测器在外加电压为5 V、光功率密度为0.15 mW/cm2的350 nm紫外光照射下的光响应度有18倍的增强，同时下降时间缩短为原来一半。之后又在CdMoO4-ZnO复合膜的表面沉积Au纳米颗粒，Au纳米颗粒沉积时间经优化后构建的探测器在相同测试条件下较原来的复合膜异质结探测器的光电流值翻倍，且下降时间再次减半。ZnO薄膜与CdMoO4微米片间形成的Type-II型异质结有效地增强了复合膜探测器的光电性能。而来自Au纳米颗粒的热电子注入到复合膜后进一步增加了整体光电流。停止光照后，Au纳米颗粒与复合膜间形成的肖特基势垒阻碍了载流子的传导而加速了电流的衰减。本研究对Au纳米颗粒修饰的CdMoO4-ZnO复合膜探测器的研究为构建基于ZnO膜的新型高性能光探测器提供了新的方法和思路。在该基金的支持下，以项目申请人为通讯作者，已经在材料类著名杂志上发表论文23 篇，申请中国专利2项，受邀在Chemical Reviews撰写了相关的综述论文。受邀在美国召开的NanoWorld Conference 2018等国际大会上做大会/特邀报告5次，与国内外多个课题组开展合作交流研究。该国家基金参与培养5位博士后，3位博士生生和3位硕士生。