Data from: Prediction for electronic, vibrational and thermoelectric properties of chalcopyrite AgX(X=In,Ga)Te2: PBE+U approach

The electronic, vibrational and thermoelectric transport characteristics of AgInTe2 and AgGaTe2 with chalcopyrite structure have been investigated. The electronic structures are calculated using the density-functional theory (DFT) within the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) functional considering the Hubbard-U exchange-correlation. The band-gaps of AgInTe2 and AgGaTe2 are much larger than previous standard GGA functional results and agree well with the existing experimental data. The effective mass of the hole and the shape of density of states near the edge of the valence band indicate AgInTe2 and AgGaTe2 are considerable p-type thermoelectric materials. An analysis of lattice dynamics shows the low thermal conductivities of AgInTe2 and AgGaTe2. The thermoelectric transport properties' dependence on carrier concentration for p-type AgInTe2 and AgGaTe2 in a wide range of temperatures has been studied in detail. The results show that p-type AgInTe2 and AgGaTe2 at 800 K can achieve the merit values of 0.91 and 1.38 at about 2.12×10^20 cm^-3 and 1.97×10^20 cm^-3 carrier concentrations, respectively. This indicates p-type AgGaTe2 is a potential thermoelectric material at high temperature.

本研究针对具有黄铜矿结构（chalcopyrite structure）的AgInTe₂与AgGaTe₂的电子、振动及热电输运特性展开了系统探究。研究采用基于Perdew-Burke-Ernzerhof（PBE）广义梯度近似（GGA）的密度泛函理论（DFT），结合哈伯德U（Hubbard-U）交换关联修正，对两种材料的电子结构进行了计算。结果显示，AgInTe₂与AgGaTe₂的带隙远大于传统标准GGA泛函的计算结果，且与已有实验数据吻合良好。空穴有效质量与价带边缘附近的态密度分布表明，AgInTe₂与AgGaTe₂均为性能优异的p型热电材料。晶格动力学分析证实，两种材料均具备较低的热导率。本研究详细探究了宽温度区间内，p型AgInTe₂与AgGaTe₂的热电输运特性随载流子浓度的变化规律。结果表明，在800 K温度下，当载流子浓度分别约为2.12×10²⁰ cm⁻³与1.97×10²⁰ cm⁻³时，p型AgInTe₂与AgGaTe₂的热电优值可分别达到0.91与1.38。这一结果显示，p型AgGaTe₂是一种极具应用潜力的高温热电材料。