[1]陈慧,魏志勇,陈伟宇,等.掺杂硅纳米薄膜法向热导率的分子动力学模拟[J].东南大学学报(自然科学版),2017,47(3):490-494.[doi:10.3969/j.issn.1001-0505.2017.03.013]
　Chen Hui,Wei Zhiyong,et al.Molecular dynamics simulation of out-of-plane thermal conductivity of doped silicon nanofilms[J].Journal of Southeast University (Natural Science Edition),2017,47(3):490-494.[doi:10.3969/j.issn.1001-0505.2017.03.013]
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掺杂硅纳米薄膜法向热导率的分子动力学模拟()
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《东南大学学报(自然科学版)》[ISSN:1001-0505/CN:32-1178/N]

卷:
47
期数:
2017年第3期
页码:
490-494
栏目:
能源与动力工程
出版日期:
2017-05-20

文章信息/Info

Title:
Molecular dynamics simulation of out-of-plane thermal conductivity of doped silicon nanofilms
作者:
陈慧1; 2; 魏志勇1; 陈伟宇1; 刘晨晗1; 毕可东1; 陈云飞1
1东南大学机械工程学院, 南京 211189; 2江苏海事职业技术学院船舶与海洋工程学院, 南京 211170
Author(s):
Chen Hui1;  2;  Wei Zhiyong1;  Chen Weiyu1;  Liu Chenhan1;  Bi Kedong1;  Chen Yunfei1
1School of Mechanical Engineering, Southeast University, Nanjing 211189, China
2Department of Ship and Ocean Engineering, Jiangsu Maritime Institute, Nanjing 211170, China
关键词:
硅纳米薄膜;  热导率;  掺杂;  分子动力学;  声子平均自由程;  热导率累积函数
Keywords:
silicon nanofilm;  thermal conductivity;  doping;  molecular dynamics;  phonon mean free path;  thermal conductivity accumulation function
分类号:
TK124
DOI:
10.3969/j.issn.1001-0505.2017.03.013
摘要:
采用非平衡态分子动力学方法计算了平均温度为300 K时膜厚2.2~104.4 nm的硅纳米薄膜以及掺锗的硅纳米薄膜的法向热导率.采用随机掺杂方式在硅纳米薄膜中掺入锗原子,掺杂浓度分别为5%和50%.模拟结果表明,相同膜厚的掺锗硅薄膜的法向热导率比纯硅薄膜的法向热导率小很多,掺杂前后的硅薄膜法向热导率均随着膜厚的增大而增大.通过计算体态硅热导率关于声子平均自由程的累积函数,发现对体态硅热导率主要贡献是声子平均自由程为2~2 000 nm的声子,而掺锗的体态硅中对热导率贡献约占80%的声子平均自由程为0.1~30 nm,远小于纯硅中对热导率主要贡献的声子平均自由程.
Abstract:
The out-of-plane thermal conductivities of both pure silicon nanofilm and that doped with germanium(Ge)with film thicknesses ranging from 2.2 to 104.4 nm were calculated by non-equilibrium molecular dynamics(NEMD)simulation at an average temperature of 300 K. Ge atoms were doped in a random pattern with a doping density of 5% and 50%, respectively. The results show that there is a large reduction in thermal conductivities of the silicon nanofilm after doping with the same thickness. The out-of-plane thermal conductivity of the Ge-doping silicon nanofilm as well as that of a pure one increases with the increase of the film thickness. By calculating the thermal conductivity accumulation function in terms of phonon mean free path(MFP), it indicates that at 300 K the dominant contribution to the bulk thermal conductivity of pure silicon comes from phonons with MFPs between 2 and 2 000 nm, while the MFPs of phonons that contribute about 80% to the bulk thermal conductivity of Ge-doping silicon are between 0.1 and 30 nm, thus they are much less than those of the pure silicon.

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备注/Memo

备注/Memo:
收稿日期: 2016-09-16.
作者简介: 陈慧(1982—),女,博士生;陈云飞(联系人),男,博士,教授,博士生导师,yunfeichen@seu.edu.cn.
基金项目: 国家自然科学基金资助项目(51205061, 51375092).
引用本文: 陈慧,魏志勇,陈伟宇,等.掺杂硅纳米薄膜法向热导率的分子动力学模拟[J].东南大学学报(自然科学版),2017,47(3):490-494. DOI:10.3969/j.issn.1001-0505.2017.03.013.
更新日期/Last Update: 2017-05-20