卤素钙钛矿阻变存储器的可微缩特性研究

The study of the scalability of halide perovskite based resistance switching memory

近年来,卤素钙钛矿阻变存储器由于在柔性可穿戴设备上的潜在应用而开始受到研究者们的广泛关注。然而,这种材料能否最终实现产业化还取决于其阻变器件是否具备可微缩特性。为了研究这种特性,采用溶液法加工了三明治结构的Au/Cs0.06 FA0.78 MA0.16 Pb(I0.92 Br0.08)3/ITO阻变存储器,并使用改变前驱体溶液浓度的方法来控制阻变层的厚度。通过扫描电子显微镜(SEM)图像研究了阻变薄膜的材料特性和薄膜厚度,研究了膜厚与前驱体溶液浓度的数学关系,验证了通过改变前驱体溶液浓度的方法调控钙钛矿薄膜厚度的可行性。在此基础上,测试研究了每种厚度下20个器件的电学特性,统计分析了其I-V阻变特性、forming电压、SET/RESET电压、窗口值、保持特性和耐久性。总结了forming电压、SET/RESET电压随厚度变化的规律,并通过对阻变薄膜的导电机制和阻变机制的分析研究,验证了由卤素空位形成的导电通道的通断主导的阻变特性。

Halide perovskite based resistance random access memory(RRAM)has attracted researchers'attention in recent years because of its potential application in flexible wearable electronic equipment.However,the industrialization of this material also depends on whether its resistive switching devices can be scaled down or not.To investigate this characteristic,we fabricated the Cs0.06FA0.78MA0.16Pb(I0.92Br0.08)3 based RRAM sandwiched with Au and ITO by the solution method,and controlled the thickness of the halide perovskite resistance layer by using different concentrations precursor solutions.The characteristics of surface and thickness of resistance layer were studied by scanning electron microscope(SEM)images,and the relationship between film thickness and solution concentration of precursor was studied further.Thus,the feasibility of controlling the thickness of perovskite film by changing the concentration of the precursor solution was verified.On this basis,we statistically analyzed the I-V resistive switching behaviors,forming voltage,SET/RESET voltage,retention and endurance by investigating the electrical characteristics of 20 devices of each thickness.The forming voltage and SET/RESET voltage as the dependence of thickness of film were summarized,and the formation and rupture of the conductive filaments composed of halide vacancies were verified to be the crucial factor of resistive switching behaviors through the analysis on its conductive mechanism and switching mechanism.