Kaur Prabhjot, Bera Chandan
Institute of Nano Science and Technology, Habitat Centre, Phase-10, Sector-64, Mohali, Punjab 160062, India.
Phys Chem Chem Phys. 2017 Sep 20;19(36):24928-24933. doi: 10.1039/c7cp05170k.
The effect of alloying on the thermoelectric properties of cobaltite, CoAsS, and paracostibite, CoSbS, has been investigated in this study. Density functional theory and the Boltzmann transport equation have been applied to explore the role of phonon-phonon scattering and atomistic scattering due to alloying in phonon transport. An almost 44% reduction in thermal conductivity of CoAsSbS alloy compared to pure CoAsS and an ∼15% reduction in thermal conductivity of CoAsSbS compared to pure CoSbS were found. Simultaneously, the thermoelectric (TE) figure of merit (ZT) increased by ∼11% in p-type CoAsSbS alloy and ∼8% in n-type CoAsSbS alloy as compared to their base pure materials at 800 K. We found that by tuning the composition of CoAsSbS alloy, very similar ZT values for both p-type and n-type can be achieved in a large temperature range. We also calculated the TE properties of CoAsSeS and CoSbSSe alloys. This study will help in designing CoAsSbS based alloys for efficient thermoelectric devices.
本研究考察了合金化对钴硫砷矿（CoAsS）和副硫锑钴矿（CoSbS）热电性能的影响。采用密度泛函理论和玻尔兹曼输运方程，探讨了合金化过程中声子-声子散射和原子散射在声子输运中的作用。结果发现，与纯CoAsS相比，CoAsSbS合金的热导率降低了近44%；与纯CoSbS相比，CoAsSbS的热导率降低了约15%。同时，在800 K时，与基础纯材料相比，p型CoAsSbS合金的热电（TE）优值（ZT）提高了约11%，n型CoAsSbS合金的ZT提高了约8%。我们发现，通过调整CoAsSbS合金的成分，在较宽的温度范围内，p型和n型合金都能获得非常相似的ZT值。我们还计算了CoAsSeS和CoSbSSe合金的TE性能。该研究将有助于设计基于CoAsSbS的合金，用于高效热电装置。
