无铅二维钙钛矿阻变存储器的机理及性能调控研究

Recently, halide perovskites have received attention as the storage material for resistance random access memory devices due to their superior properties, including a small exciton binding energy, long carrier lifetime and low nonradiative carrier recombination rate. However, the poor device stabilities attributed to their intrinsic material instability and the toxicity of soluble Pb2+ must be resolved before stepping toward to practical applications. In this project, the high stable lead-free two-dimensional layered perovskite will be synthesized using the solution-based method ((PEA)2SnBr4). The memory devices with different electrodes will be fabricated. The relationship between resistive characteristics and metal electrodes will be investigated. To understand the resistive switching mechanisms, the EDX mapping images and XPS depth profile analysis of the memory devices will be characterized. To improve the performance of the devices, the doping impurities into the resistive switching layer will be adopted by the ion implantation method. The effect of the doping parameters on the improvement of switching performance will be studied and the corresponding mechanisms will be systematically discussed. The achievements of this project will provide experimental and theoretical basis for development of new materials for resistance random access memory devices, and manufacture of the new generation resistive switching memory with high performance.

卤化物钙钛矿由于具有载流子扩散能力长和激子结合能小等优点，受到阻变存储器领域的特别关注。然而，三维卤化物钙钛矿的不稳定性以及可溶性Pb2+的有毒性，阻碍了其实际应用。本项目拟合成高稳定性的Sn基二维层状卤化物钙钛矿((PEA)2SnBr4)，并以此为存储材料制备环境友好型阻变器件。研究不同金属电极下器件的阻变特性，利用EDX和XPS等深度剖析手段，揭示阻变机理并建立相应的物理模型。在此基础上，利用离子注入方法对存储材料层进行可控掺杂，提高器件的阻变性能，研究可控掺杂参数（剂量和能量）和性能之间的定量调节关系，揭示器件的性能受控调节机制。本项目的实施将为新型高稳定阻变存储材料的研发及高性能阻变器件的研制提供重要的理论和实验依据。

卤化物钙钛矿由于具有载流子扩散能力长和激子结合能小等优点，受到阻变存储器领域的特别关注。针对三维卤化物钙钛矿的不稳定性以及可溶性Pb2+的有毒性，我们合成出高质量无铅且具有高稳定性的钙钛矿，并构建高性能忆阻器，突破了目前性能的局限性。本项目主要研究内容是合成出高质量无铅全无机Cs3Cu2Br5和CsSnBr3钙钛矿薄膜,并构建了具有优异阻变性能的忆阻器。主要结果及关键数据如下：（1）利用旋涂法合成出高质量无铅Cs3Cu2Br5薄膜，构建的忆阻器呈现出优异的双极性阻变特性，包括超低的读写电压（0.45, -0.39 V）、合适的开关比（102）、优异的保持特性（>104）以及在80%相对湿度下优异的稳定性；(2) 利用一步溶液法合成出高质量无铅全无机CsSnBr3薄膜，构建具有优异稳定性的柔性忆阻器，同时实现了超低的工作电压（0.2, -0.15 V）和高的开关比（105）。本项目的实施为新型高稳定阻变存储材料的研发及高性能阻变器件的研制提供重要的理论和实验依据。