Thermal conductivity of magnesium selenide (MgSe)–A first principles study
Thermal conductivity of magnesium selenide (MgSe)–A first principles study
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DOI：
10.1016/j.commatsci.2021.110679
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发表时间：
2021-10
影响因子：
3.3
通讯作者：
Rajmohan Muthaiah;J. Garg
中科院分区：
文献类型：
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作者：
Rajmohan Muthaiah;J. Garg
近年来，宽带隙半导体在电力电子、热电和高温领域的应用越来越受到人们的关注。硒化镁（MgSe）是一种宽禁带半导体，因其电子、磁性、光学和结构特性而被广泛研究。本文报道了不同晶相的硒化镁（MgSe）晶格导热系数与温度和长度的关系；锌闪锌矿（ZB）、岩盐（RS）、纤锌矿（WZ）和砷镍（NiAs）采用第一性原理计算。我们的第一性原理计算结果表明，含knnea <岩盐< kurtzite < kzincblite的MgSe具有较低的导热系数。我们系统地研究了弹性常数、声子频率、声子散射率和模式贡献热导率。我们的第一性原理计算表明，由于强烈的声子-声子散射，NiAs相的室温热导率为4.54 Wm−1K−1，锌闪石结构的室温热导率为21.27 Wm−1K−1，声子带隙引起的声子-声子散射非常低。我们的研究结果表明，具有低导热系数的MgSe（NiAs）化合物和具有高导热系数的MgSe（ZB）化合物将分别成为热电应用和热管理系统的有前途的材料。
Wide bandgap semiconductor has recently attracted attraction for power electronics, thermoelectric and high temperature applications. Magnesium Selenide (MgSe) is a wide bandgap semiconductor extensively studied for its electronic, magnetic, optical and structural properties. In this work, we report the temperature and length dependence lattice thermal conductivity of magnesium selenide (MgSe) with different crystallographic phase; zincblende (ZB), rocksalt (RS), wurtzite (WZ) and nickel arsenic (NiAs) using first principles computations. Our first principles calculations results shows a low thermal conductivity of MgSe withkNiAs<krocksalt<kwurtzite<kzincblende. We systematically investigated the elastic constants, phonon frequencies, phonon scattering rate and mode contribution thermal conductivity. Our first principles calculations shows a room temperature low thermal conductivity of 4.54 Wm−1K−1for the NiAs phase due to the strong phonon–phonon scattering and 21.27 Wm−1K−1for the zincblende structure very low phonon–phonon scattering arising from the phonon bandgap. Our results elucidate that MgSe(NiAs)compounds with low thermal conductivity and MgSe(ZB)with high thermal conductivity will be a promising material for thermoelectric applications and thermal management systems respectively.