Two-Dimensional SiP, SiAs, GeP and GeAs as Promising Candidates for Photocatalytic Applications

Abstract

Group IV–V-type layered materials, such as SiP, SiAs, GeP and GeAs, are among the most attractive two-dimensional (2D) materials that exhibit anisotropic mechanical, optical and transport properties. In this short communication, we conducted density functional theory simulations to explore the prospect of SiP, SiAs, GeP and GeAs nanosheets for the water-splitting application. The semiconducting gaps of stress-free SiP, SiAs, GeP and GeAs monolayers were estimated to be 2.59, 2.34, 2.30 and 2.07 eV, respectively, which are within the desirable ranges for the water splitting. Moreover, all the considered nanomaterials were found to yield optical absorption in the visible spectrum, which is a critical feature for the employment in the solar water splitting systems. Our results furthermore confirm that the valence and conduction band edge positions in SiP, SiAs, GeP and GeAs monolayers also satisfy the requirements for the water splitting. Our results highlight the promising photocatalytic characteristics of SiP, SiAs, GeP and GeAs nanosheets for the application in solar water splitting and design of advanced hydrogen fuel cells.

2D layered SiP as anisotropic nonlinear optical material

“…In this manner, SiAs, GeAs, GeAs 2 , GeAs, GeP and SiP as the members of a novel group IV-V 2D semiconductor family have gained a growing attention 25 – 27 due to their promising linear optical properties and low crystal symmetries. Specifically, SiP has been shown as an excellent optical material with a large band gap of 1.71 eV, fast photoresponse and strong anisotropy 28 , 29 .…”

As2S3, As2Se3 and As2Te3 nanosheets: superstretchable semiconductors with anisotropic carrier mobilities and optical properties

“…Worthy to mention that among all areas for the application of 2D materials, energy storage and conversion systems are among the most appealing and attractive ones. In particular, the production of hydrogen fuel via the solar water splitting and design of advanced rechargeable metal-ion batteries, using the 2D materials as active building blocks have been extensively explored during the last decade [32]. The tremendous interests toward the employment of 2D materials in the energy storage/conversion systems originate from their large surface to volume ratio, outstanding mechanical flexibility, remarkably high electron mobility and chemical and thermal stabilities.…”

Observation of 2D Conduction in Ultrathin Germanium Arsenide Field-Effect Transistors

“…Numerical calculations and optical band gap measurements indicate that germanium arsenide indirect band gap ranges from ∼0.57 to 0.65 eV for the bulk 19 , 20 to 1.6–2.1 eV for the monolayer. 24 , 25 …”