This study is aimed at evaluating the structural stability, lattice thermal conductivity, transport properties and the thermoelectric figure of merit of scandium copper chalcogenides (denoted by ScCuX₂) based on first principles. At the apex of this work, we explored the transport properties by solving Boltzmann transport equations in a relaxation time approximation to obtain transport coefficients of interest which were then integrated with lattice thermal conductivity in order to establish the values of the dimensionless figure of merit (ZT), which dictate not only the possibility of using a given material as a major component in the design of thermoelectric system but also indicates how efficient it is in converting thermal to electrical energy, where values of ZT around unity are preferred.

At room temperature (300 K), the values of the averaged lattice thermal conductivity obtained are 1.58, 1.28 and 1.47 W/mK for ScCuS₂, ScCuSe₂ and ScCuTe₂ respectively which are promising for thermoelectric applications where minimal values of lattice thermal conductivity are desirable. We also evaluated the Debye temperatures as well as transverse and longitudinal sound velocity in ScCuX₂ compounds. In addition, group velocities, phonon lifetimes and mean free paths were explored in order to uncover the mechanisms of thermal transport in these ternaries. Our study provides important new insights into heat transport and phonon scattering mechanisms in ScCuX₂ ternary compounds. From our findings, among the three ternary compounds, ScCuSe₂ has the highest value of dimensionless figure of merit of 0.65 at high temperatures (1000 K) when the majority charge carriers are holes having a carrier concentration of 10¹⁹ cm⁻³.

本研究旨在评估scan铜硫属元素化物的结构稳定性，晶格热导率，输运性能和热电性能（由ScCuX表示）。${}_2$）基于第一原则。在这项工作的顶点，我们通过在弛豫时间近似中求解玻尔兹曼输运方程来探索输运性质，以获得感兴趣的输运系数，然后将其与晶格热导率进行积分，以建立无量纲品质因数（ZT）的值。），这不仅决定了在热电系统设计中使用给定材料作为主要成分的可能性，而且还表明了将热能转换为电能的效率，其中ZT值最好为1。

在室温（300 K）下，ScCuS的平均晶格热导率值为1.58、1.28和1.47 W / mK${}_2$，ScCuSe${}_2$ 和ScCuTe${}_2$分别对于希望晶格热导率的最小值是理想的热电应用是有希望的。我们还评估了ScCuX中的德拜温度以及横向和纵向声速${}_2$化合物。此外，探索了群体速度，声子寿命和平均自由程，以揭示这些三元系中的热传递机理。我们的研究为ScCuX中的传热和声子散射机理提供了重要的新见解${}_2$三元化合物。根据我们的发现，在三种三元化合物中，ScCuSe${}_2$ 当大多数电荷载流子为载流子浓度为10的空穴时，在高温（1000 K）下具有0.65的无量纲品质因数的最大值${}^{19}$ 厘米${}^{-3}$。