论文类型：期刊论文
第一作者：徐萌
通讯作者：缪向水,徐明
合写作者：Ho,Kai-Ming,Cai-Zhuang,Wang,Songyou,程晓敏,童浩,薛堪豪,乔崇,徐萌
发表刊物：Journal of Materials Chemistry C
所属单位：华中科技大学
学科门类：工学
一级学科：电子科学技术
文献类型：J
卷号：6
期号：1
DOI码：10.1039/D0TC01089H
发表时间：4378-02-01
摘要：Phase change memory is an excellent candidate for next-generation memory technologies with a high operation speed, but the memory capacity is not very satisfactory, due to which engineers have to add the 3D stacking technology (3D XPoint) for new products. Alternatively, multi-level storage is an easy approach to enable large data density and probably future neuromorphic computing. Lately, K2Sb8Se13 has attracted considerable attention as a multi-level phase change material because it exhibits an interesting amorphous-to-amorphous (polyamorphic) transformation before crystallization, and these two polyamorphic states as well as the crystalline phase show distinct resistances, adding a new data state to the existing “0” and “1”. Understanding and stabilizing this new amorphous state is the key to the application of this material; here, we have investigated these two amorphous states through ab initio simulations. We found that these two states showed obvious differences in the local structures, and the void concentration revealed by the low-electron-density areas indicated stronger interactions between the atomic clusters in the denser phase. The density of states and electron localization function were analyzed and we confirmed that adding electronic holes were largely responsible for the decrease in resistance. In this work, we have discovered the origin of multi-level resistance states in K2Sb8Se13, paving the way for the design of new phase change memory devices based on this material.
发布期刊链接：https://pubs.rsc.org/en/content/articlelanding/2020/tc/d0tc01089h