Liu Qingsong, Chen Zimin, Zhou Xianzhong
School of Information Engineering, Guangdong University of Technology, 510006 Guangzhou, China.
School of Electronics and Information Technology, Sun Yat-Sen University, 510275 Guangzhou, China.
ACS Omega. 2022 Mar 31;7(14):11643-11653. doi: 10.1021/acsomega.1c06367. eCollection 2022 Apr 12.
The electronic, thermal, and thermoelectric transport properties of ε-GaO have been obtained from first-principles calculation. The band structure and electron effective mass tensor of ε-GaO were investigated by density functional theory. The Born effective charge and dielectric tensor were calculated by density perturbation functional theory. The thermal properties, including the heat capacity, thermal expansion coefficient, bulk modulus, and mode Grüneisen parameters, were obtained using the finite displacement method together with the quasi-harmonic approximation. The results for the relationship between the Seebeck coefficient and the temperature and carrier concentration of ε-GaO are presented according to the ab initio band energies and maximally localized Wannier function. When the carrier concentration of ε-GaO increases, the electrical conductivity increases but the Seebeck coefficient decreases. However, the figure of merit of thermoelectric application can still increase with the carrier concentration.
ε-GaO的电子、热和热电输运性质已通过第一性原理计算获得。采用密度泛函理论研究了ε-GaO的能带结构和电子有效质量张量。利用密度微扰泛函理论计算了玻恩有效电荷和介电张量。采用有限位移法并结合准谐近似得到了包括热容、热膨胀系数、体模量和模式格林艾森参数在内的热性质。根据从头算能带能量和最大局域化万尼尔函数给出了ε-GaO的塞贝克系数与温度和载流子浓度之间关系的结果。当ε-GaO的载流子浓度增加时，电导率增加但塞贝克系数减小。然而，热电应用的优值仍可随载流子浓度增加。
