Tunable electronic properties and electric-field-induced phase transition in phosphorene/graphene heterostructures

Abstract

The shortcomings of mono-component systems, e.g., the gapless nature of graphene, the lack of air-stability in phosphorene, etc. have drawn great attention toward stacked materials expected to show interesting electronic and optical properties. Using the tight-binding approach and the Green's function method, we investigate the electronic properties of armchair-edged lateral phosphorene/graphene heterostructures, which are either semiconductor/semiconductor or semiconductor/metal heterostructures, depending on the width of graphene ribbon. It is found that the system is narrow-gapped, and the bandgap can be modulated by tuning the size of the domains. Besides, the analysis of the bandgap variation against the width of the component phosphorene ribbon indicates that, in semiconductor/metal heterostructure, phosphorene ribbon does not induce any electronic state near the Fermi level, suggesting that the suppressed electron transport should be attributed to the hole transfer across the interface. Furthermore, we show that the transverse electric field can significantly diversify the electronic behavior of the heterostructure, i.e., the heterostructure undergoes the semiconductor-metal phase transition. Moreover, tuning the transverse electric field yields an intriguing possibility that the system can undergo a topological phase transition from a band insulator to a topological insulator.

Electronic transport and thermoelectric properties of phosphorene nanodisk under an electric field

“…where E is the electron energy, I is the identity matrix, η is an arbitrarily small positive number, H C is the central region (or device) Hamiltonian, and Σ SC(DC) is the self-energy for the source (drain) lead. Details about this formalism can be found in [16,31].…”

“…The chemical stability of black phosphorus is better than that of red and white ones [1]. Phosphorene is a direct bandgap semiconductor (>1.5 eV) with high carrier mobility [8,[13][14][15][16]. The lattice thermal conductivity for phosphorene in the zigzag direction is higher than it is in the armchair direction [15,17].…”

“…The lattice thermal conductivity for phosphorene in the zigzag direction is higher than it is in the armchair direction [15,17]. Although, phosphorene is unstable when exposed to air, to overcome this challenge, it is usually sandwiched between other materials [16]. Tailoring nanostructures can change their physical properties, and for phosphorene, despite it being an intrinsic semiconductor, its zigzag nanoribbon has a metallic behavior [18].…”

Tuning conducting phases in C3N/C2N heterostructures: applications in thermoelectrics

“…12 Heterostructures, which consist of two or more materials, open new ways for combining and altering physical properties for specific purposes. [13][14][15][16][17] The thermal conductivity of C 3 N monolayer with different porosity, which resembles C 2 N, is studied using molecular dynamics, 18 and the thermal conductivity of C 3 N and C 2 N monolayers evaluated 589 W mK À1 and 52 W mK À1 , respectively, by increasing the porosity, the thermal transport behavior can be changed and reduced up to B15 W mK À1 . A DFT study shows the MoS 2 monolayer-graphene heterostructure has a higher power factor up to B2 times than graphene and MoS 2 , due to the change in the electronic structure.…”

First-principles insights onto structural, electronic and optical properties of Janus monolayers CrXO (X = S, Se, Te)

“…The large-scale research turned to search alternate 2D materials including graphene-like structures when shortcomings of graphene emerged. Consequently, a series of 2D nanomaterials have been reported, such as phosphorene, 7,8 Xene (stanene, 9 silicene 10 or germanene), 11,12 hexagonal boron nitride (h-BN), 13 transition metal chalcogenides (TMDs) 14,15 and so forth. They possess many superior mechanical, electronic, and photocatalytic properties which do not exist in 2D forms.…”