Strain-enhanced properties of Janus Si2PAs monolayer as a promising photocatalyst for the splitting of water: Insights from first-principles calculations

Tunable electronic and photoelectric properties of Janus group-III chalcogenide monolayers and based heterostructures

“…Due to its lattice asymmetry, the Janus monolayers has an intrinsic built-in electric field in the vertical direction compare with traditional MXs, which can separate the charge carriers and enhance the electron-phonon interaction [26][27][28] . In addition, Janus MX monolayers showed distinct physical properties such as excellent absorption coefficient, high charge carrier mobility, and rapid separation of photogenerated carriers, which gives them potential for photovoltaic and photoelectric applications 29,30 . For instance, the Janus In 2 SSe monolayer possesses an indirect-direct bandgap transition due to the broken vertical symmetry 31 .…”

“…To confirm the origin of the catalytic activity of vertical heterojunction, density of states (DOS) calculations and Bader charge analysis were performed. In the process of heterojunction optimization and computation, the DFT-D3 method with Grimme correction is adopted to describe the long-range van der Waals interactions 50 . Additionally, the more accurate Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional was employed to check the reliability of the band structure 51 .…”

Cu- and Al-Decorated Monolayer TiSe2 for Enhanced Gas Detection Sensitivity: A DFT Study

“…Since the discovery of two-dimensional (2D) materials − such as graphene, its special properties such as high specific surface area, perfect biocompatibility, and high electron mobility provide promising applications in gas detection, pollutant treatment, electrode materials, supercapacitors, hydrogen production, hydrogen storage, solar energy conversion, etc. − Studies have shown that graphene and MoS 2 have excellent potential for gas sensing, but they are not highly selective for different gases, , so there is a need to develop new materials for gas detection. Monolayer titanium diselenide (TiSe 2 ), one of transition-metal selenides, is now obtainable on a large scale through chemical vapor deposition (CVD). , Similar to graphene, it boasts a high surface area and is notably recognized for its charge density wave (CDW) phase transition, impacting electrical conductivity and electronic properties. , Research, both experimental and theoretical, has delved into its applications in energy storage, photocatalysis, and magnetism …”

Electronic structures and optical properties of Janus GeXY (X, Y = P, As and Sb): First-principles predictions

“…These results are higher than other Janus photocatalytic materials, such as PtSSe (1 × 10 5 cm −1 ), 30) WSSiN 2 (1.6 × 10 5 cm −1 ), 31) and Si 2 PAs (2.4 × 10 5 cm −1 ) monolayers. 20) In addition, the exciton binding energies of GeAsP, GeSbP, and GeAsSb are 256, 363, and 220 meV, respectively, which are smaller than MoS 2 (540 meV) and comparable to GeSe (320 meV). 32,33) It indicates that the free electrons and holes generated in the Janus GeXY monolayers can be easily separated from each other, which is beneficial for improving photocatalytic efficiency.…”

“…19) Guo et al performed DFT calculations on the structural stability of the Janus Si 2 PAs monolayer and found that strained modulated Si 2 PAs monolayer can be an excellent photocatalyst for the splitting of water. 20) However, 2D Ge-based P-group materials with a Janus structure have rarely been reported.…”