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

TL;DR

This study explores the tunable electronic properties and electric-field-induced phase transitions in phosphorene/graphene heterostructures, revealing controllable bandgaps and topological phase changes using theoretical modeling.

Contribution

It introduces a detailed theoretical analysis of phosphorene/graphene heterostructures, demonstrating electric-field-induced phase transitions and tunable electronic properties.

Findings

The heterostructure exhibits a narrow bandgap that can be modulated by domain size.

Electric fields can induce a semiconductor-metal phase transition.

Tuning the electric field can cause a topological phase transition from a band insulator to a topological insulator.

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.