Govindaraj Prakash, Sivasamy Mugundhan, Murugan Kowsalya, Venugopal Kathirvel, Veluswamy Pandiyarasan
Department of Physics and Nanotechnology, SRM Institute of Science and Technology Chennai-603 203 India
School of Interdisciplinary Design and Innovation (SIDI), Indian Institute of Information Technology Design and Manufacturing Chennai-600 127 India
RSC Adv. 2022 Apr 26;12(20):12573-12582. doi: 10.1039/d2ra00805j. eCollection 2022 Apr 22.
The pressure induced structural, electronic, transport, and lattice dynamical properties of ZnGaTe were investigated with the combination of density functional theory, Boltzmann transport theory and a modified Debye-Callaway model. The structural transition from 4̄ to 4̄2 occurs at 12.09 GPa. From the basic observations, ZnGaTe is found to be mechanically as well as thermodynamically stable and ductile up to 12 GPa. The direct band gap of 1.01 eV is inferred from the electronic band structure. The quantitative analysis of electron transport properties shows that ZnGaTe has moderate Seebeck coefficient and electrical conductivity under high pressure, which resulted in a large power factor of 0.63 mW m K (750 K). The ultralow lattice thermal conductivity (∼1 W m K at 12 GPa) is attributed to the overlapping of acoustic and optical phonon branches. As a result, the optimal figure of merit of 0.77 (750 K) is achieved by applying a pressure of 12 GPa. These findings support that ZnGaTe can be a potential p-type thermoelectric material under high pressure and thus open the door for its experimental exploration.
结合密度泛函理论、玻尔兹曼输运理论和修正的德拜 - 卡拉韦模型，研究了压力诱导的ZnGaTe的结构、电子、输运和晶格动力学性质。从4̄到4̄2的结构转变发生在12.09吉帕。从基本观察结果来看，发现ZnGaTe在高达12吉帕的压力下在机械和热力学上都是稳定的且具有延展性。从电子能带结构推断出其直接带隙为1.01电子伏特。对电子输运性质的定量分析表明，ZnGaTe在高压下具有适中的塞贝克系数和电导率，这导致在750 K时功率因子高达0.63毫瓦每米开尔文。超低的晶格热导率（在12吉帕时约为1瓦每米开尔文）归因于声学和光学声子分支的重叠。结果，通过施加12吉帕的压力，实现了0.77（750 K）的最佳品质因数。这些发现支持ZnGaTe在高压下可以成为一种潜在的p型热电材料，从而为其实验探索打开了大门。
