Electronic and Thermal Properties of $\text{GeTe/Sb}_{2}\text{Te}_{3}$ Superlattices by ab-initio Approach: Impact of Van der Waals Gaps on Vertical Lattice Thermal Conductivity
arXiv (Cornell University)(2021)
摘要
In the last decade, several works have focused on exploring the material and electrical properties of $\text{GeTe/Sb}_{2}\text{Te}_{3}$ superlattices (SLs) in particular because of some first device implementations demonstrating interesting performances such as fast switching speed, low energy consumption, and non-volatility. However, the switching mechanism in such SL-based devices remains under debate. In this work, we investigate the prototype $\text{GeTe/Sb}_{2}\text{Te}_{3}$ SLs, to analyze fundamentally their electronic and thermal properties by ab initio methods. We find that the resistive contrast is small among the different phases of $\text{GeTe/Sb}_{2}\text{Te}_{3}$ because of a small electronic gap (about 0.1 eV) and a consequent semi-metallic-like behavior. At the same time the out-of-plane lattice thermal conductivity is rather small, while varying up to four times among the different phases, from 0.11 to 0.45 W/m$^{-1}$K$^{-1}$, intimately related to the number of Van der Waals (VdW) gaps in a unit block. Such findings confirm the importance of the thermal improvement achievable in $\text{GeTe/Sb}_{2}\text{Te}_{3}$ super-lattices devices, highlighting the impact of the material stacking and the role of VdW gaps on the thermal engineering of the Phase-Change Memory cell.
更多查看译文
关键词
thermal conductivity,thermal properties,superlattices,van der waals gaps,ab-initio
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要