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Temperature-dependent electron-phonon renormalization of band gaps from ab initio GW and GW perturbation theory

ORAL

Abstract

The temperature-dependent electron-phonon (e-ph) renormalization of band gaps of semiconductors has been extensively studied from first principles using density functional theory (DFT)-based methods. However, the description of the many-electron correlation (self-energy) effects for electron states with the static exchange-correlation potential in standard DFT may limit the accuracy of the results. Here, we perform ab initio GW and linear-response GW perturbation theory (GWPT) calculations to investigate the e-ph renormalization of the fundamental band gaps of diamond, silicon, and gallium phosphide at different temperatures, where self-energy effects beyond DFT are included from first principles. We find that many-electron self-energy effects enhance the e-ph renormalization compared with the results using density functional perturbation theory (DFPT) for all three materials. Moreover, the temperature dependence of the band gaps predicted by GW and GWPT shows excellent agreement with experimental measurements, with significant improvements from results using DFPT. These findings highlight the crucial role of many-electron effects in the temperature-dependent e-ph renormalization of semiconductor band gaps.

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Presenters

  • Xiaoxun Gong

    Department of Physics, University of California at Berkeley, Berkeley, CA, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

Authors

  • Xiaoxun Gong

    Department of Physics, University of California at Berkeley, Berkeley, CA, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Zhenglu Li

    University of Southern California, Unviersity of Southern California, Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA

  • Steven G Louie

    University of California, Berkeley, University of California, Berkeley and Lawrence Berkeley National Lab, University of California, Berkeley and Lawrence Berkeley National Laboratory, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Department of Physics, University of California at Berkeley, Berkeley, CA, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA