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.
|Original language||English (US)|
|Journal||Chemistry of Materials|
|State||Published - Aug 11 2021|
Bibliographical noteKAUST Repository Item: Exported on 2021-08-13
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.
ASJC Scopus subject areas
- Materials Chemistry
- Chemical Engineering(all)