2D and bulk h-MgSe materials from MgmSen (m, n = 1–3) clusters: Density functional investigation

An investigation in detail on the structure, electronic and thermodynamic properties for a series of group II and VI Combined hybrid alloy clusters, viz, MgmSen (m,n = 1–3) is performed, under density functional theory (DFT). The geometries of all clusters has been optimized by employing a very popular and reliable exchange-correlation functional, viz, Becke’s 3 parameter exchange with Lee-Yang-Parr correlation functional (B3LYP). The influence of adding of group II and/or group VI elements on the electronic properties is also addressed in the present work. A sincere effort has been tendered to identify any potential cluster motif from the considered series for utilizing as the building block for prospective metal-insulator-semiconductor (MIS) materials at the bulk scale. Accordingly, with an achievement of exceptionally stable rhombus shaped and D2h symmetric Mg2Se2, we have investigated structure and electronic properties of 2D hexagonal magnesium selenide (2D h-MgSe) as well as hexagonal magnesium selenide at bulk scale (bulk h-MgSe). It is evident from the present study that although 2D planar h-MgSe reveals as an insulator with the direct band gap 4.20 eV whereas bulk h-MgSe come out to be a semiconductor material with direct band gap as 1.13 eV. The bulk h-MgSe phase is reported to be an exceptionally stable semiconductor in the magnesium selenide family.