Controllable Band Alignment Transition in InSe–MoS₂ Van der Waals Heterostructure

Abstract

Van der Waals (vdW) heterojunctions with type‐II band alignment, in which electrons and holes are localized in distinct layers, play a central role in optoelectronic devices and solar cells. The present study analyzes a type‐I→II band alignment transition in InSe–MoS2 vdW heterostructure, proposed to be controlled via changing interlayer distance or applying perpendicular external electric field. The band position shift of InSe relative to that of MoS2 attributes to a surface polarization mechanism. Changing band offset into type II facilitates possible use and allows greater flexibility for band engineering of InSe–MoS2 heterostructure in optoelectronic and solar energy applications. The present findings provide theoretical guidance to a new approach to improve the optoelectronic properties of vdW heterostructures.

Point Defects in Two-Dimensional Indium Selenide as Tunable Single-Photon Sources

“…An analysis of the band dispersion in gure S1b (where SOC is considered) highlights that the two band structures are very similar, particularly around the top of the valence band and the bottom of the conduction band, which is the most relevant part when interested in photons emission. Bandgaps are also very similar, in agreement with [6]. In conclusion, in view of the negligible dierences observed in the predicted properties of InSe monolayer, all results in this article have been obtained without including spin-orbit coupling.…”

Molybdenum disulfide–graphene van der Waals heterostructures as stable and sensitive electrochemical sensing platforms

“…Vertical interfacing of dissimilar atomic layers to form van der Waals (vdWs) structures has received enormous potential from the recent past, and a variety of synergetic effects due to charge redistribution and structural changes have been observed from such structures [25][26][27]. Such structures stabilized in sub-nanometre separation have sharp electronic boundaries [28] and it leads to inter-layer charge transfer within the layers of different work functions [29].…”

Analytic dependence of the Madelung constant on lattice parameters for 2D and 3D metal diiodides (MI2) with CdI2 (2H polytype) layered structure

“…Note that the above coefficients practically coincide with those achieved in this study: k 1 =−0.2516, k 2 =1.5741, and k 3 =−0.1631 (see section 3.2). Table A2 of the appendix presents : (i) the data of the lattice parameters {a, c, u} of FeI 2 measured in above mentioned experimental study [44] by x-ray diffraction technique at ambient pressure (≈0 GPa) and at different values of the applied hydrostatic pressure P=4, 7.8, 12.5, 16.9 GPa and (ii) the data for the flatness parameter f and the Madelung constant A M calculated correspondingly according to equations (7) and (2) with the use of above experimental data {a, c, u} [44]. With the use of the data from table A2, figure 4 presents for FeI 2 the plot of the Madelung constant A M versus the } data points plotted according to equation (8).…”

“…In terms of atomic bonding, in such a type materials the strength of atomic bonding in individual layers (intralayer cohesive energy) substantially prevails over that of the atomic bonding between layers (interlayer cohesive energy). Typical examples of layered materials are graphite [3,4], metal dichalcogenides (e.g., MoS 2 , WS 2 , MoSe 2 , MoTe 2 , and BiS 2 ) [5][6][7][8][9], metal dihalides (e.g., CdI 2 , FeI 2 , CoBr 2 , and MnCl 2 ) [2], metal dihydroxides (e.g., Co(OH) 2 , Mn(OH) 2 , and Ca(OH) 2 ) [2,10], and some materials with other chemical compositions [1,2,6] . Physicochemical properties of individual layers and 2D nanosheets of layered materials mostly change dramatically from those of their parent 3D materials [3,4,6,10].…”