Investigation of Electronic Properties of AlGaSe/GaSe Heterostructure: A Denstiy Functional Study

The scientific community has shown significant interest in the field of two-dimensional (2D) materials. Due to the phenomenon of quantum confinement in a specific direction, 2D materials exhibit fascinating properties that are not present in their bulk form. With the emergence of semiconducting 2D materials, there is a wide array of electronic properties to explore, opening up exciting possibilities for the development of next-generation electronics. An emerging class of materials includes the III-VI monochalcogenides, with indium selenide (InSe) and gallium selenide (GaSe) being two prominent members. Unlike transition metal dichalcogenides, researchers have been drawn to investigate the underlying physical phenomena and technological applications of materials with high intrinsic mobility and a direct bandgap at small thicknesses. In this work, we explore the structural and electronic characteristics of AlGaSe/GaSe heterstructure by density functional theory. The GaSe forms a relatively weak bond with the AlGaSe monolayer, exhibiting an adsorption energy of 9.089 meV/atom. It is found that the heterobilayer is energetically favourable, with an interlayer distance of 3.379 Å, indicating a van der Waals (vdW) type interaction. The most stable stacking configuration is confirmed with different deposition sequences. The AlGaSe/GaSe heterostructure exhibits an indirect band gap semiconductor characteristic, with a bandgap value of 1.774 eV. Our findings showcase the exciting possibilities for creating novel two-dimensional nanoelectronic devices using the vdW heterostructure.