Electronic, optical, and thermoelectric properties of Janus In-based monochalcogenides

Abstract

Inspired by the successfully experimental synthesis of Janus structures recently, we systematically study the electronic, optical, and electronic transport properties of Janus monolayers In2XY (X/Y = S, Se, Te with X № Y) in the presence of a biaxial strain and electric field using density functional theory. Monolayers In2XY are dynamically and thermally stable at room temperature. At equilibrium, both In2STe and In2SeTe are direct semiconductors while In2SSe exhibits an indirect semiconducting behavior. The strain significantly alters the electronic structure of In2XY and their photocatalytic activity. Besides, the indirect-direct gap transitions can be found due to applied strain. The effect of the electric field on optical properties of In2XY is negligible. Meanwhile, the optical absorbance intensity of the Janus In2XY monolayers is remarkably increased by compressive strain. Also, In2XY monolayers exhibit very low lattice thermal conductivities resulting in a high figure of merit ZT, which makes them potential candidates for room-temperature thermoelectric materials.

Anisotropic thermal and electrical transport properties induced high thermoelectric performance in an Ir2Cl2O2 monolayer

“…In the past decades, reducing the dimensionality of the TE material as a practical approach to improving the TE performance was studied. [8][9][10] Generally, layered structures have ultralow lattice thermal conductivities since the interface interactions between the neighboring layers lead to a large phonon anharmonicity. Therefore, layered structures were predicted as promising TE materials.…”

Computational insights into structural, electronic, and optical properties of Janus GeSO monolayer

“…24,25 Beside the Janus structures of TMDs, Janus monochalcogenides have also been of great interest in recent years. 26,27 Guo and co-worked demonstrated that the Janus group III monochalcogenides have much higher piezoelectric coefficients than that of the corresponding group-III monochalcogenide monolayers. 28 These Janus structures have also been proven to have efficient photocatalytic performance.…”

Tunable Electronic Properties of Novel 2D Janus MSiGeN4 (M = Ti, Zr, Hf) Monolayers by Strain and External Electric Field

“…[14] Many subsequent studies have focused on the 2D Janus structures and the heterostructures formed from these new materials. [15][16][17][18][19][20] With their vertical broken mirror symmetry structure, they have had many extraordinary physical properties with potential applications in the fields of materials science, energy conversion, and spintronics. [21][22][23] Recently, a new 2D structure MoSi 2 N 4 has been successfully fabricated by chemical vapor deposition.…”