The Verification of Thermoelectric Performance Obtained by High-Throughput Calculations: The Case of GeS2 Monolayer From First-Principles Calculations

Xiaolian Wang,Wei Feng,Zhehao Sun,Chen Shen,Yuchen Wu,Mao Yang,Xiaoqiang Wu,Hangbo Qi,Yonghui Liu

doi:10.3389/fmats.2021.709757

Abstract

Electronic fitness function (EFF, achieved by the electrical transport properties) as a new quantity to estimate thermoelectric (TE) performance of semiconductor crystals is usually used for screening novel TE materials. In recent years, because of the high EFF values, an increasing number of two-dimensional materials have been predicted to have the potential for TE applications via high-throughput calculations. Among them, the GeS2 monolayer has many interesting physical properties and is being used for industrial applications. Hence, in this work, we systematically investigated the TE performance, including both electronic and thermal transport properties, of the GeS2 monolayer with first-principles calculations. The results show that the structure of the GeS2 monolayer at 700 K is thermally unstable, so we study its TE performance only at 300 and 500 K. As compared with other typical TE monolayers, the GeS2 monolayer exhibits excellent electronic transport properties but a relatively high lattice thermal conductivity of 5.71 W m−1 K−1 at 500 K, and thus an unsatisfactory ZT value of 0.23. Such a low ZT value indicates that it is necessary to consider not only the electron transport properties but also the thermal transport properties to screen the thermoelectric materials with excellent performance through high-throughput calculations.

Highlights

In the past decades, the development of environment-friendly renewable energy has been the main task since it has alleviated the current global energy crisis and the greenhouse effect to some extent (Biswas et al, 2012; Wang and Wu, 2012; Tan et al, 2016)
The results show that this monolayer exhibits great electronic properties, for example, high PF value (3.4 mW m−1 K−2) at 300 K, which is consistent with the high EFF values obtained with high-throughput computations
This study suggests that the GeS2 monolayer has poor TE performance, proving that the method of predicting high-efficiency TE materials according to the EFF values obtained via high-throughput computations may be incomplete

Summary

INTRODUCTION

The development of environment-friendly renewable energy has been the main task since it has alleviated the current global energy crisis and the greenhouse effect to some extent (Biswas et al, 2012; Wang and Wu, 2012; Tan et al, 2016). This study suggests that the GeS2 monolayer has poor TE performance, proving that the method of predicting high-efficiency TE materials according to the EFF values obtained via high-throughput computations may be incomplete. RTA tends to overestimate power factors, because of computational convenience, we still adopt this approximation It was used in a study on the electronic transport properties of two-dimensional triphosphides (InP3, GaP3, SbP3, and SnP3) (Sun et al, 2020). For the electronic thermal conductivity κe, in this study, it is obtained using the Wiedemann–Franz law, that is, κe LσT (Jonson and Mahan, 1980) Besides, κe can be obtained directly from the BoltzTraP2 code, that is, κe κ0 − TσS2 (Madsen et al, 2018) A recent study put forward that the results which were obtained from the output of BoltzTraP and from using the Wiedemann–Franz law agree very well with each other (Li M. et al, 2019)

RESULTS AND DISCUSSION

CONCLUSION

DATA AVAILABILITY STATEMENT