Ab initio study of enhanced thermal conductivity in ordered AlGaO3 alloys
Ab initio study of enhanced thermal conductivity in ordered AlGaO3 alloys
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DOI：
10.1063/1.5131755
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发表时间：
2019-12
影响因子：
4
通讯作者：
Sai Mu;H. Peelaers;C. D. Walle
中科院分区：
文献类型：
--
作者：
Sai Mu;H. Peelaers;C. D. Walle
从声子Boltzmann输运方程出发，利用密度泛函理论计算了单斜β Ga 2 O3和有序AlGaO 3合金的晶格热导率，并计算了其简谐力常数和三阶非简谐力常数.β- Ga 2 O3的热导率计算值与实验值吻合较好.我们证明，最低能量的结构的Al 0.5 Ga 0.5合金，这是有序的，有一个热导率提高了70%以上，相比β- Ga 2 O 3。我们将这种增强归因于（1）群速度的增加和（2）由于加权相空间的减小而导致的非谐散射率的减小。这一发现为改善氧化镓器件的散热提供了一条途径.
We compute the lattice thermal conductivity of monoclinic β- Ga 2 O 3 and the ordered AlGaO 3 alloy from the phonon Boltzmann transport equation, with the harmonic and third-order anharmonic force constants calculated from density functional theory. The calculated thermal conductivity of β- Ga 2 O 3 is consistent with experiment. We demonstrate that the lowest-energy structure of an Al 0.5 Ga 0.5 alloy, which is ordered, has a thermal conductivity that is raised by more than 70% compared to β- Ga 2 O 3. We attribute the enhancement to (1) increased group velocities and (2) reduced anharmonic scattering rates due to the reduced weighted phase space. The findings offer an avenue toward improved heat dissipation from Ga 2 O 3 devices.