Band alignment and optical features in Janus-MoSeTe/X(OH)₂ (X = Ca, Mg) van der Waals heterostructures

Abstract

van der Waals heterostructures can be effectively used to enhance the electronic and optical properties and extend the application range of two-dimensional materials.

Mechanical and electronic properties of graphitic carbon nitride (g-C3N4) under biaxial strain

“…5c). Previous studies [40,[42][43][44][45] on other 2D honeycomb materials have proven that the band gap calculated by DFT obeys similar strain-dependency, suggesting that the electronic properties can be effectively regulated by changing strain, and g-C 3 N 4 is so flexible that may have potential applications in flexible devices. In addition, we have also calculated the PBE high transition probabilities between the upper most valence band (VB) and the lowest conduction band (CB) of g-C 3 N 4 , which are shown by the squares of the dipole transition matrix elements [46], P 2 , at k points in Fig.…”

“…This is because HSE06 corrects the underestimation of band gap by partially removing the self interaction. Previous studies have shown that the hybrid-functional HSE06 method shows significant improvement of band gap of 2D materials [40][41][42][43]. Moreover, both PBE and HSE06 methods have shown the same variation trends of gap-strain curves.…”

“…S2a-S2d, at 0% and 10% strain, showing the D6h symmetry, mainly because the biaxial deformation is subjected to the equibiaxial case. This is really different from these uniaxial and shear deformations [40,42,43,47], which can induce symmetry-breaking. The projected density of states (PDOS) of g-C 3 N 4 without strain in Fig.…”

Spin–orbit coupling effect on electronic, optical, and thermoelectric properties of Janus Ga2SSe

“…4 The successful synthesis of Janus MoSSe opened a new chapter in the research for the 2D family and many different types of Janus structures were theoretically studied recently. [6][7][8][9] Janus structures show a high prospect for use as thermoelectric materials due to their owning a high thermoelectric gure of merit. 10 With suitable band edge alignment, Janus structures are expected to be used in photocatalytic water splitting.…”

“…15 Recently, van der Waals heterostructures based Janus monolayers have been studied with a lot of attention. 7,16,17 In graphene/Ga 2 SSe heterostructures, a small band gap has been found in graphene due to weak interactions between graphene and Ga 2 SSe. 17 It implies that forming heterostructures with the Janus structure is one of the ways to overcome the gapless disadvantage of graphene.…”