Electronic Transport of Two-Dimensional Ultrawide Bandgap Material h-BeO

TL;DR

This study predicts that monolayer h-BeO, a two-dimensional ultrawide bandgap material, exhibits high electronic mobility and tunable properties under strain, making it promising for high-power and ultraviolet optoelectronic applications.

Contribution

First-principles calculations reveal the electronic structure and transport properties of monolayer h-BeO, highlighting its high mobility and strain-tunable electronic characteristics.

Findings

Monolayer h-BeO has an indirect bandgap of 7.05 eV.

High room-temperature mobility of 473 cm^2/Vs due to electron-phonon interactions.

Strain can increase mobility to approximately 1000 cm^2/Vs.

Abstract

Two-dimensional ultrawide bandgap materials, with bandgaps significantly wider than 3.4 eV, have compelling potential advantages in nano high-power semiconductor, deep-ultraviolet optoelectronics, and so on. Recently, two-dimensional layered h-BeO has been synthesized in the experiments. In the present work, the first-principles calculations predict that monolayer h-BeO has an indirect bandgap of 7.05 eV with the HSE functional. The ultrawide bandgap results from the two atomic electronegativity difference in the polar h-BeO. And the electronic transport properties are also systematically investigated by using the Boltzmann transport theory. The polar LO phonons of h-BeO can generate the macroscopic polarization field and strongly couple to electrons by the Frohlich interaction. Limited by the electron-phonon scattering, monolayer h-BeO has a high mobility of 473 cm^2/Vs at room temperature. Further studies indicate that the biaxial tensile strain can reduce the electronic effective mass and enhance the electron-phonon coupling strength. The suitable strain can promote the mobility to ~1000 cm^2/Vs at room temperature.