Journal of Shanghai University(Natural Science Edition) ›› 2026, Vol. 32 ›› Issue (1): 33-43.doi: 10.12066/j.issn.1007-2861.2700

• Materials Science • Previous Articles    

Temperature-dependent band gap of thermoelectric PbTe from first-principles calculations

GAN Lu, YANG Jiong, XI Jinyang   

  1. Materials Genome Institute, Shanghai University, Shanghai 200444, China
  • Received:2025-07-03 Published:2026-03-16

Abstract: The band gap is one of the most fundamental properties of semiconductors. Manystudies have demonstrated that temperature-induced vibrations have a significant impact on the band gap. In this paper, the band structure of the thermoelectric compound PbTe at finite temperature is investigated using first-principles calculations, focusing on the effects of electron-phonon renormalization (EPR) and spin-orbit coupling (SOC) on the temperature-dependentband gap. The results reveal that EPR leads to temperature- dependent variations in the band gap of PbTe, while the inclusion of SOC reverses the trend of band gap change (without SOC, the band gap decreases by 88 meV as the temperature rises from 0 K to 750 K, while the band gap increases by 144 meV with SOC). Furthermore, the zero-point renormalization contributes minimally to the band gap change. Therefore, both EPR and SOC effects have a significant influence on the band gap of PbTe and must be taken into account. This paper provides theoretical insight into the temperature dependence of PbTe’s band gap and ofiers guidance for optimizing its thermoelectric performance.

Key words: first-principles, thermoelectric PbTe, electron-phonon renormalization (EPR), spin-orbit coupling (SOC), temperature-dependent band gap

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