Hydrogenation and Fluorination of 2D Boron Phosphideand Boron Arsenide: A Density Functional Theory Investigation

摘要

First-principles density functional theory calculations are performed to study the stability and electronic properties of hydrogenated and fluorinated two-dimensional sp³ boron phosphide (BP) and boron arsenide (BAs). As expected, the phonon dispersion spectrum and phonon density of states of hydrogenated and fluorinated BX (X = P, As) systems are found to be different, which can be attributed to the different masses of hydrogen and fluorine. Hydrogenated BX systems bear larger and indirect band gaps and are found to be different from fluorinated BX systems. These derivatives can be utilized in hydrogen storage applications and ultrafast electronic devices. Finally, we investigated the stability and electronic properties of stacked bilayers of functionalized BP. Interestingly, we found that these systems display strong interlayer interactions, which impart strong stability. In contrast with the electronic properties determined for the fluorinated/hydrogenated monolayers, we found that the electronic properties of these bilayers can finely be tuned to a narrow gap semiconductor,metallic or nearly semimetallic one by selecting a suitable arrangementof layers. Moreover, the nearly linear dispersion of the conductionband edge and the heavy-, light-hole bands are the interesting characteristics.Furthermore, the exceptional values of effective masses assure thefast electronic transport, making this material very attractive toconstruct electronic devices.