First principles prediction of the electronic structure and carrier mobilities of biaxially strained molybdenum trioxide (MoO3)

Abstract

The electronic band structures of unstrained and biaxially strained MoO3 were determined by first-principles density functional theory calculations. From the band structures, the effects of strain on the charge carrier mobilities were investigated. These mobilities were calculated based on deformation potential theory. First, we found that the electron effective masses of unstrained bulk pristine MoO3 are about three times smaller than the corresponding hole effective masses, and, second, the electron mobility is about ten times the hole mobility, making the compound an electron transport material. Our results also show that, when compressed biaxially, as the strain increases from 0% to 1.5%, the electron (hole) mobility increases by 0% to 53% (0% to 17%). On the other hand, the application of a biaxial tensile strain decreases the electron (hole) mobility by 65% to 0% (90% to 0%), as the tensile strain increases from 0% to 1.5 %. These changes are caused mainly by the fact that the carrier effective masses reduce (increase) upon application of compressive (tensile) strain. Only the acoustic-phonon limited carrier mobilities were computed; hence, the actual mobilities cannot be less than the values obtained in this work.