Ultrahigh Carrier Mobility in the Two-Dimensional Semiconductors B8Si4, B8Ge4, and B8Sn4

Sun, Minglei; Luo, Yi; Yan, Yuan; Schwingenschlögl, Udo

Ultrahigh Carrier Mobility in the Two-Dimensional Semiconductors B8Si4, B8Ge4, and B8Sn4

Embargo End Date

2022-08-11

Type

Article

Authors

Sun, Minglei

Luo, Yi

Yan, Yuan
Schwingenschlögl, Udo

KAUST Department

Computational Physics and Materials Science (CPMS)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division

Online Publication Date

2021-08-11

Print Publication Date

2021-08-24

Date

2021-08-11

Submitted Date

2021-05-27

Abstract

Based on evolutionary search and first-principles calculations, we predict for B8Si4 structural stability in terms of cohesive energy, phonon spectrum, and melting point. The size of the indirect band gap is similar to that of bulk Si, and the electronic transport turns out to be highly anisotropic for both holes and electrons. The predicted structure prototype is shared by B8Ge4, B8Sn4, and B8Pb4. B8Ge4 is an indirect band gap semiconductor, with the hole mobility similar to that of B8Si4. B8Sn4 is an indirect band gap semiconductor with the gap size similar to that of bulk Ge. The hole mobility of B8Sn4 turns out to be as high as ∼106 cm2 V–1 s–1 and the electron mobility as high as ∼105 cm2 V–1 s–1, exceeding the performance of graphene (2 × 105 cm2 V–1 s–1). B8Pb4 is found to be metallic.

Citation

Sun, M., Luo, Y., Yan, Y., & Schwingenschlögl, U. (2021). Ultrahigh Carrier Mobility in the Two-Dimensional Semiconductors B8Si4, B8Ge4, and B8Sn4. Chemistry of Materials. doi:10.1021/acs.chemmater.1c01824

Acknowledgements

The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). Computational resources were provided by the KAUST supercomputing laboratory. We thank Dr. Qisheng Wu of Brown University for discussions on the calculation of mechanical properties and Dr. Zhiyong Zhu of KAUST for assistance with the supercomputer.