Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Department of Optical Science and Engineering, Fudan University, Shanghai, 200433, China.
Phys Chem Chem Phys. 2018 Jul 11;20(27):18200-18206. doi: 10.1039/c8cp00901e.
In this study, bipolar memristive behaviors were systematically characterized in Ag/Sb2Te3/Ag hetero-junctions. By using in situ Raman and photoluminescence spectroscopy, a direct observation of the bonding environment and band structure confirmed that resistive switches are strongly related to the electronic valence changes in Sb2Te3 and the formation of Schottky barriers at Ag/Sb2Te3 interfaces. Band movement of Sb2Te3 acquired by first-principles calculations also supports the electrostatic barrier charging as a memristive mechanism of Ag/Sb2Te3/Ag heterocells. Independent resistance-switching behaviors that can be utilized in both amorphous and crystalline Sb2Te3 lead to multiple resistance values with a large memory window (104-105) and low read voltage (∼0.2 V), giving rise to a unique multi-level memory concept. This study based on Ag/Sb2Te3/Ag hetero-junctions offers a significant understanding to promote the use of Sb2Te3 and other chalcogenide memristors as promising candidates for compatible high-density memory applications.
在这项研究中，我们系统地研究了 Ag/Sb2Te3/Ag 异质结中的双极忆阻行为。通过原位拉曼和光致发光光谱，我们直接观察到键合环境和能带结构，证实了电阻开关与 Sb2Te3 中的电子价态变化以及 Ag/Sb2Te3 界面处肖特基势垒的形成密切相关。第一性原理计算得到的 Sb2Te3 能带移动也支持了静电势垒充电作为 Ag/Sb2Te3/Ag 异质结忆阻机制。独立的电阻开关行为可以在非晶态和晶态 Sb2Te3 中得到利用，导致多个电阻值具有较大的存储窗口（104-105）和较低的读取电压（约 0.2 V），从而产生了独特的多级存储概念。这项基于 Ag/Sb2Te3/Ag 异质结的研究为促进 Sb2Te3 和其他硫属化物忆阻器的应用提供了重要的理解，有望成为高密度兼容存储器应用的有前途的候选材料。
