相转变调控二维过渡金属硫化物基柔性阻变存储器阻变效应及其阻变机理研究

In this project, according to the demands of flexible resistive switching memory devices with high storage density, low power consumption, fast speed and simple structure for flexible electronic devices, we devote ourselves to the research of the phase transformation regulating resistive switching behaviors and resistive switching mechanisms of two-dimensional transitional metal dichalcogenides (2D TMDs) based flexible resistive switching memory devices. By controlling the phase structure transformation degree of 2D TMDs nanosheets, the concentration of sulfur vacancy in the 2D TMDs nanosheets based resistive switching layer is regulated. The regulation law of the effect of sulfur vacancy concentration on resistive effect is found. The alternation from bipolar to unipolar resistive switching is observed in the flexible resistive switching devices, which results in multilevel memory. By comparing and analyzing the resistive switching behaviors in the resistive layer with different sulfur vacancy concentrations, the internal physical mechanisms of the regulation of the resistive switching behaviors by sulfur vacancy concentrations and the alternation from bipolar to unipolar resistive switching are investigated. The results of this project help to set up the experimental and theoretical basis for the applications of 2D TMDs with various phase structures in high-performance flexible resistive switching memory devices, which advance electronic information technology developments.

本项目根据柔性电子器件对具有存储密度高、功耗低、速度快、结构简单等特点的柔性阻变存储器的需求，展开相转变对二维过渡金属硫化物基柔性阻变存储器阻变效应的调控及其机理研究。通过控制二维过渡金属硫化物纳米片相结构转变程度，调控基于复合相二维过渡金属硫化物纳米片阻变层中的硫空位浓度，探索硫空位浓度调控阻变效应的规律，使柔性阻变存储器具有可逆转变的单双极阻变效应，实现多态存储。通过对比分析具有不同硫空位浓度阻变层的阻变效应，研究阻变层中硫空位浓度对阻变效应调控的机理和单双极阻变效应可逆转变的内在物理机制。该项目实施有助于为具有多种相结构的二维过渡族金属硫化物在高性能柔性阻变存储器中的应用提供实验基础和理论依据，对电子信息技术的发展具有重要意义。

本项目根据可穿戴设备、智能终端、生物医疗等领域对新型柔性阻变存储器的需求，对于基于二维材料的柔性阻变存储器进行研究。通过简单的溶液法制备得到质量较好的基于二维纳米片的薄膜。通过相转变的策略来控制MoS2纳米片基体中金属相的含量，进而调控以混合相MoS2纳米片薄膜为阻变层的柔性阻变存储器的阻变性能。根据计划书安排，首先探索了实现2H相MoS2纳米片基体相转变的方法，使金属相的含量最高达到80%。然后通过旋涂法、真空抽滤法制备了混合相MoS2纳米片的薄膜，对薄膜的成膜质量进行了研究，并构建了基于该薄膜的柔性阻变存储器，对其阻变性能进行研究。接着制备了基于不同金属相含量的MoS2纳米片柔性阻变存储器件，得到了双极阻变效应和WORM阻变效应，对空位浓度在阻变效应中的作用进行了分析，探讨了空位浓度在导电细丝形成和断裂过程中的作用，为具有多种相结构的二维过渡族金属硫化物在高性能柔性阻变存储器中的应用提供实验和理论依据。