Heterostructures of two-dimensional transition metal dichalcogenides: Formation, ab initio modelling and possible applications

Abstract

State-of-the-art technologies of fabrication of transition metal dichalcogenide monolayers like MeX2, where Me = Mo, W; X = S, Se, Te, and their based heterostructures are considered. Results of theoretical modeling are analyzed and possibilities of band gap engineering by means of strains, impurities, vacancies, various layer stacking and combination of different materials are presented. It is shown that vacancies and impurities in the positions of metal atoms may drastically change the band gap, even leading to an appearance of metallic properties, whereas a substitution of chalcogen atoms by isovalent atoms changes the properties not so dramatically. Possible applications of heterostuctures with tunable band gaps for creation of transistors, light-emitting diodes, photoelectrochemical cells or photovoltaic devices are proposed and their advantages in comparison with commonly used analogues are discussed.

Charge Critical Phenomena in a Field Heterostructure with Two-Dimensional Crystal

“…These include both two-dimensional (2D) semi-conductors [1][2][3][4] and materials with unusual electronic states, such as topological insulators and topological semi-metals [5][6][7][8][9]. Currently, 2D semi-conductors, with a particular focus on transition metal dichalcogenides (TMDs) and heterostructures on this basis, are emerging as serious candidates for future solid-state information processing and storage device technology [10]. Their potential consists in improved device scaling and energy-efficient switching compared to traditional bulk semi-conductors, such as Si, Ge and AIII-BV compounds [2].…”

“…Along with numerous studies of the properties of the above materials, including ab initio calculations [6,10], little attention has previously been paid to the study of their charge properties, manifested in field heterostructures. Investigation of charge phenomena in metal M (field electrode)/insulator I/semi-conductor S field heterostructures (FHS MISs) is highly relevant, since they form the root of the elemental base of modern information processing and storage devices.…”