Electronic and Optical Properties of the Type‐II GaN/SiH van der Waals Heterostructure: A First‐Principles Study

Abstract

In recent years, constructing van der Waals (vdW) heterostructures based on different 2D materials has been a highly effective way to obtain desired electronic and optical properties. Herein, on the basis of first‐principles calculations, a 2D vdW heterostructure is constructed by vertically stacking the indirect‐bandgap gallium nitride (GaN) and silicane (SiH) monolayers. For the formed heterostructure, the structural, electronic, and optical properties are all computed. The obtained results show that the heterostructure is a direct‐bandgap semiconductor with typical type‐II band alignment. Furthermore, the linearly tunable bandgap, together with the robust type‐II band alignment, can be realized by applying vertical strains or external electric fields. It is also found that both monolayers exhibit the same UV absorption range and the notably enhanced UV absorption is obtained after forming the heterostructure. In particular, the maximum absorptivity can reach to 21.6%. These results are expected to provide useful references for the design of ultraviolet optoelectronic devices based on the 2D GaN/SiH vdW heterostructure.

Tunability of the electronic properties and electrical contact in graphene/SiH heterostructures

“…This interlayer separation is consistent with that in other SiH-based heterostructures. 41,51,52 Moreover, to check the stability of the GR/SiH heterostructure, the binding energy is calculated as E b = [ E GR/SiH − E GR − E SiH ]/ A , where E GR/SiH , E GR and E SiH are the total energies of the GR/SiH heterostructure, isolated GR and SiH monolayers, respectively. A is the surface area of the heterostructure.…”

“…This interlayer separation is consistent with that in other SiH-based heterostructures. 41,51,52 Moreover, to check the stability of the GR/SiH heterostructure, the binding energy is calculated as…”

Type-II 2D AgBr/SiH van der Waals heterostructures with tunable band edge positions and enhanced optical absorption coefficients for photocatalytic water splitting

“… 49 This exploration seeks to investigate the viability of SiH-based hetero-junctions for photocatalytic applications. Rese-arch has also revealed that a GaN/SiH vdW heterostructure has an increased optical absorption rate compared to a GaN mono-layer, 50 reaching a peak of 21.6% in the UV region. Furthermore, an AlAs/SiH vdW heterostructure exhibits an impressive high optical absorption coefficient in the visible light region, measuring 2.2 × 10 5 cm −1 .…”