应变对硒化锡和硫化锡拉胀材料力学性质和能带结构的调控  

Effects of strain on mechanical and electronic properties of Sn Se and Sn S auxetic materials

作　　者：方武章 张礼川 闫清波[2] 郑庆荣[1] 苏刚[1] 

机构地区：[1]中国科学院大学物理科学学院,北京100049 [2]中国科学院大学材料科学与光电技术学院,北京100049

出　　处：《中国科学院大学学报（中英文）》2017年第1期8-14,共7页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(11574309);国家重点基础研究发展(973)计划项目(2012CB932901)资助

摘　　要：硒化锡(Sn Se)和硫化锡(Sn S)是具有广泛应用前景的热电材料和光电材料。通过应用第一性原理方法,系统地研究硒化锡和硫化锡的力学性质和能带结构,探讨应变对其性质的影响。发现这些性质是各向异性的。计算应变-应变曲线、杨氏模量、声子谱、声速和应变下的能带结构。发现硒化锡和硫化锡是具有负泊松率的拉胀材料,它们可用于传感器和生物医学等领域;在Z方向施加单轴-5%到5%的应变时,硒化锡的带隙从0.7 e V变到1.03 e V,硫化锡的带隙从0.85 e V变到1.41 e V,表明应变是调控硒化锡和硫化锡太阳能转换效率的一种有效方法。Sn Se and Sn S are promising thermoelectric and optoelectronic materials. By means of the first-principle calculations, we systematically calculate the mechanical properties and electronic structures of Sn Se and Sn S and also investigate the effects of strain on these properties. We find that these properties are anisotropic. We calculate the strain-strain curve,Young ＇s modulus,phonon dispersion,sound velocity,and the band structures under strain. We find that Sn Se and Sn S are auxetic materials with negative Poisson ratio which can be used in sensor and biomedicine. When strain is applied along the Z direction from- 5% to 5%,the band gap of Sn Se changes from 0. 7 e V to 1. 03 e V while the band gap of Sn S changes from 0. 85 e V to 1. 41 e V,which indicates that strain is an effective method for improving the conversion efficiencies of Sn Se and Sn S as solar cell materials.

关 键 词：硒化锡 硫化锡 第一性原理计算 负泊松率 应变调控 

分 类 号：O47[理学—半导体物理]