Gupta Raveena, Kumar Naveen, Kaur Prabhjot, Bera Chandan
Institute of Nano Science and Technology, Habitat Center, Phase-X, Mohali, Punjab-160062, India.
Phys Chem Chem Phys. 2020 Sep 14;22(34):18989-19008. doi: 10.1039/d0cp03117h. Epub 2020 Aug 19.
The global energy crisis demands the search for new materials for efficient thermoelectric energy conversion. Theoretical predictive modelling with experiments can expedite the global search of novel and ecoconscious thermoelectric materials. The efficiency of thermoelectric materials depends upon the thermoelectric figure of merit (ZT). In this perspective, we discuss the theoretical model to calculate thermoelectric properties. Different scattering mechanisms of electrons and phonons are calculated using a simple model for the fast prediction of thermoelectric properties. Thermoelectric properties based on the simple model have shown more than 90% agreement with the experimental values. Possibility to optimize the figure of merit by alloying, defects, nanostructuring and band convergence is also discussed for layered chalcogenides of tin. In the case of doped materials, ion-impurity scattering is found to be dominating over electron-phonon scattering and the power factor can be optimized by tuning the former scattering rate. For phonon transport, alloy scattering is found to be the most dominating among all other scattering mechanisms. Theoretically, it is found that in the temperature range between 300 K and 800 K, SnSeS has the highest ZT with an efficiency of 17.20% with respect to Carnot efficiency. There could be 53.8% enhancement of the device efficiency in SnSeS compared to experimentally reported SnSeS in the medium temperature range (300 K to 800 K). Possible routes to achieve the best ZT in the medium temperature range are also discussed in this perspective.
全球能源危机促使人们寻找用于高效热电能量转换的新材料。理论预测建模与实验相结合能够加快全球范围内对新型且具有生态意识的热电材料的探索。热电材料的效率取决于热电优值（ZT）。从这个角度出发，我们讨论了用于计算热电性能的理论模型。使用一个简单模型计算电子和声子的不同散射机制，以便快速预测热电性能。基于该简单模型的热电性能与实验值的吻合度超过了90%。还讨论了通过合金化、缺陷、纳米结构化和能带收敛来优化优值的可能性，涉及锡的层状硫族化合物。对于掺杂材料，发现离子 - 杂质散射比电子 - 声子散射更占主导地位，并且通过调整前一种散射速率可以优化功率因子。对于声子输运，发现合金散射在所有其他散射机制中最为突出。理论上发现，在300 K至800 K的温度范围内，SnSeS具有最高的ZT，相对于卡诺效率而言效率为17.20%。与中温范围（300 K至800 K）内实验报道的SnSeS相比，SnSeS的器件效率可能提高53.8%。从这个角度还讨论了在中温范围内实现最佳ZT的可能途径。
