Effects of graphene/BN encapsulation, surface functionalization and molecular adsorption on the electronic properties of layered InSe: a first-principles study

Abstract

By using first-principles calculations, we investigated the effects of graphene/boron nitride (BN) encapsulation, and surface functionalization by metallic elements (K, Al, Mg and typical transition metals) and molecules (tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE)) on the electronic properties of layered indium selenide (InSe). It was found that an opposite trend of charge transfer is possible for graphene (donor) and BN (acceptor), which is dramatically different from phosphorene where both graphene and BN play the same role (donor). For an InSe/BN heterostructure, a change of the interlayer distance due to out-of-plane compression can effectively modulate the band gap. Strong acceptor abilities to InSe were found for the TCNE and TCNQ molecules. For K, Al and Mg-doped monolayer InSe, charge transfer from the K and Al atoms to the InSe surface was observed, causing an n-type conduction of InSe, while p-type conduction of InSe was observed in the case of Mg-doping. The atomically thin structure of InSe enables the possible observation and utilization of the dopant-induced vertical electric field across the interface. A proper adoption of the n- or p-type dopants allows for the modulation of the work function, the Fermi level pinning, the band bending, and the photo-adsorbing efficiency near the InSe surface/interface. Investigation of the adsorption of transition metal atoms on InSe showed that Ti-, V-, Cr-, Mn-, and Co-adsorbed InSe are spin-polarized, while Ni-, Cu-, Pd-, Ag- and Au-adsorbed InSe are non-spin-polarized. Our results shed light on the possible ways to protect InSe structures and modulate their electronic properties for nanoelectronics and electrochemical device applications.

Two-Dimensional Black Phosphorus Carbide: Rippling and Formation of Nanotubes

“…[27][28][29][30][31][32] For this reason, a new class of materials, the hybridized composites that combine the advantages and counteract the disadvantages of its constituent compounds are currently in the spotlight. [33][34][35][36][37][38] These materials can exist as heterostructures consisting of several layered 2D materials 33,[39][40][41] such as graphene/phosphorene, graphene/InSe, and boron nitride/phosphorene or 2D layers consisting of atoms of different elements. [42][43][44] It has been demonstrated that heterostructures formed by 2D materials, which are unstable in strand ambient conditions, such as phosphorene, and 2D materials, which are stable, such as graphene, are characterized by improved stabilities.…”

Photoquantum Hall Effect and Light‐Induced Charge Transfer at the Interface of Graphene/InSe Heterostructures

“…. Among these 2D materials, the “post‐transition” metal monochalcogenides, such as InSe, are receiving increasing attention . The γ‐polytype phase of InSe has a band gap that increases markedly with decreasing layer thickness down to a single layer and an interband optical spectrum ranging from the violet to the infrared .…”

On the Impact of Substrate Uniform Mechanical Tension on the Graphene Electronic Structure

“…Among them are chemical functionalization [ 8 , 9 , 10 ], the formation of graphene nanoribbons [ 11 , 12 ], mechanical strain [ 13 , 14 ], and the use of suitable substrates. It should be noted that the most proposed substrate for creating a semiconducting gap in graphene is a boron nitride substrate [ 15 , 16 , 17 , 18 , 19 ], but it is not the only possible one. Thus, properly chosen substrates can significantly change the electronic band structure of graphene [ 20 ], and, along with the mechanical stretching, it can become an alternative approach for straightforward tuning the electronic properties of graphene and obtaining a required bandgap (see Review [ 21 ] for details).…”