氧化物半导体纳米线中可逆巨电致电阻效应的机理研究

基于氧化物可逆巨电致电阻（CER）效应的电阻型随机存储器（RRAM）在性能和成本方面表现出巨大优势。但是，CER物理机制不清楚已经成为制约RRAM实用化的主要障碍。和薄膜相比，氧化物纳米线（NW）在研究CER机理方面具有独特的优势，例如，可利用电镜实时观测电激励下NW结构及微结构的变化，以及NW物理化学性能对环境敏感等。因此，研究氧化物NW CER效应，在RRAM研究领域具有重要的科学和技术意义。本项目选取n型ZnO 和p型NiO 单根NW 作为研究对象，利用可原位施加电压透射电镜、气氛和温度及光照可变电学探针台等测试手段，结合第一性原理计算，系统研究结构、微结构、化学成分、气氛、光照、温度、掺杂、电极材料等因素对NW CER影响规律。通过本项目的研究，我们希望能阐明二元氧化物NW可逆CER发生机制，深入理解氧化物CER内在机理，从而为RRAM 存储器件设计提供理论指导。

As a denser, faster and less energy-consuming non-volatile.memory, which is based on colossal electroresistance (CER) effects, resistance random access memory (RRAM) has attracted increasing attention. It is extremely important to clarify CER mechanism since the ambiguousness of CER mechanism has severely restricted the development of oxide-based RRAMs. Compared to oxide thin films, oxide nanowires (NWs) show unique advantages on CER mechanism investigation, such as feasible in situ observation of structure and micro-structure variations of NWs by transmission electron microscope (TEM) and enviorment-sensitive physical and chemical properties of NWs. In this project, both n-type ZnO and p-type NiO NWs are selected to study CER mechanism of oxides. By an in situ TEM method and electrical probe station with variable enviroments as well as first principle calculation, the effects of structure, micro-structure, chemical composition, atmosphere, illumination, temperature, doping, and electrode material on CER of NWs are systematically investigated. This project aims to clarify CER mechanism of oxide NWs and understand CER mechanism of oxides, therefore providing theoretical guidance for RRAM material selection and device design.