Tuning the Carrier Confinement in GeS/Phosphorene van der Waals Heterostructures

Abstract

Van der Waals (vdW) heterostructures, which have the advantage of integrating excellent properties of the stacked 2D materials by vdW interactions, have gained increasing attention recently. In this work, within the framework of density functional theory calculations, the electronic properties of vdW heterostructure composed of phosphorene (BP) in black phosphorus phase and GeS monolayer are systematically explored. The results show that the carriers are not separated for both lattice-match and lattice-mismatch heterostructures. For the lattice-match heterostructure, it is found that changing monolayer of GeS to bilayer can increase the energy difference of valence band offsets between GeS and BP, thus realizing electron-hole separation. For the lattice-mismatch heterostructure, altering the layer distance can transform the heterostructure into a typical type-I alignment, but applying the electric field or doping with 2, 3, 5, 6-tetrafluoro-7, 7, 8, 8-tetracyanoquinodimethane (F4TCNQ) can make it display a perfect desirable type-II alignment, where holes migration and electrons transfer are revealed to account respectively for the phenomenon of carrier separation. It is believed that the work would greatly enlarge the potential application of the BP-based heterostructures in photoelectronics and further stimulate the investigation enthusiasms on other fashionable heterostructures and even unassuming heterostructures in which the charming electronic properties can be modulated to emerge by various general methods.

Recent Advances in 2D Metal Monochalcogenides

“…The energy bandgap of such monolayers was verified by other methods, reported by Huang et al, Gong et al and Wang and co-workers ( Figure 2c). [80][81][82] In this work, the energy band alignment of CBM and VBM with respect to the vacuum level in MMCs with different number of layers has been estimated. The CBM exhibits a significant downshift, while the VBM remains relatively the same.…”

Electronic structure, optoelectronic properties and enhanced photocatalytic response of GaN–GeC van der Waals heterostructures: a first principles study

“…22 Based on the progress of 2D material synthesis, a new exciting eld is emerged to assemble separated 2D materials into numerical layered heterostructures in a precisely controlled sequence, namely vdW heterostructures. [23][24][25][26][27] These structures will provide many novel platforms for conducting new phenomena and fabricating future nanoelectronic devices. Due to the weak interlayer interactions, occurring in these layered vdW heterostructures, they can be easily fabricated in various common techniques.…”

Promises of Main-Group Metal Chalcogenide-Based Broken-Gap van der Waals Heterojunctions for Tunneling Field Effect Transistors

“…In practice, the electronic field is an effective approach to manipulate electronic properties of nanomaterials and nanodevices. − Here, we examine such an effect on electronic properties of the GeS/SnS 2 -1T vdW heterostructure by applying an external electric field along the z direction. The positive value indicates the direction of the electric field pointing from GeS to SnS 2 -1T layers while the negative value represents the opposite direction.…”