当前位置: X-MOL 学术ACS Appl. Mater. Interfaces › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
High and Anomalous Thermal Conductivity in Monolayer MSi2Z4 Semiconductors
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2021-09-15 , DOI: 10.1021/acsami.1c14205
Yan Yin 1 , Min Yi 1, 2 , Wanlin Guo 1
Affiliation  

The lattice thermal conductivity (κ) of a newly synthesized two-dimensional (2D) MoSi2N4 family and its associated abnormality are anatomized by ab initio phonon Boltzmann transport calculations. κ of MoSi2N4 and WSi2N4 is found to be over 400 W m–1 K–1 at 300 K. κ of MoSi2Z4 (Z = N, P, As) obeys Slack’s rule of thumb, decreasing by 1 order of magnitude from Z = N to Z = As with 46 W m–1 K–1. However, in MSi2N4 (M = Mo, Cr, W, Ti, Zr, Hf), the variation of κ with respect to M is anomalous, that is, deviating from Slack’s classic rule. For M in the same group, κ of MSi2N4 is insensitive to the average atomic mass, Debye temperature, phonon group velocity, and bond strength owing to the similar phonon structure and scattering rates. MSi2N4 with heavy group-VIB M even possesses a 3–4 times higher κ than that with light group-IVB M due to its much stronger M–N and exterior Si–N bonds and thus 1 order of magnitude lower phonon scattering rates. Nevertheless, this abnormality could be traced to an interplay of certain basic vibrational properties including the bunching strength and flatness of acoustic branches and their nearby optical branches, which lie outside of the conventional guidelines by Slack. This work predicts high κ of 2D MSi2Z4 for thermal management and provides microscopic insights into deciphering the anomalous κ of layered 2D structures.

中文翻译:

单层 MSi2Z4 半导体中的高且异常的热导率

新合成的二维 (2D) MoSi 2 N 4家族的晶格热导率 (κ)及其相关异常通过从头算声子玻尔兹曼输运计算进行解剖。的MoSi的κ 2 Ñ 4和的WSi 2 Ñ 4被发现是在400瓦米-1 ķ -1在硅化钼的300 K.κ 2 ž 4(Z = N,P,As)的拇指的服从松弛的规则,从而减少从 Z = N 到 Z = As 的 1 个数量级,其中 46 W m –1 K –1。然而,在 MSi 2 N 4(M = Mo, Cr, W, Ti, Zr, Hf),κ 相对于 M 的变化是异常的,即偏离了 Slack 的经典规则。对于同族的M,MSi 2 N 4 的κ 对平均原子质量、德拜温度、声子群速度和键强度不敏感,因为它具有相似的声子结构和散射率。微晶硅2 N 4重基团-VIB M 的 κ 甚至比轻基团-IVB M 高 3-4 倍,因为它具有更强的 M-N 和外部 Si-N 键,因此声子散射率低 1 个数量级。然而,这种异常可以追溯到某些基本振动特性的相互作用,包括声波分支及其附近光学分支的聚束强度和平坦度,这些特性超出了 Slack 的常规指南。这项工作预测了用于热管理的 2D MSi 2 Z 4 的高 κ 值,并为破译层状 2D 结构的异常 κ 提供了微观见解。
更新日期:2021-09-29
down
wechat
bug