Layer-Dependent Electronic and Optical Properties of 2D Black Phosphorus: Fundamentals and Engineering

TL;DR

This paper reviews the layer-dependent electronic and optical properties of 2D black phosphorus, emphasizing how interlayer interactions influence its tunable bandgap and excitonic behavior, with insights into engineering these properties for future applications.

Contribution

It provides a comprehensive summary of black phosphorus's fundamental properties, focusing on layer dependence and methods to control its electronic and optical characteristics.

Findings

Black phosphorus exhibits strong layer-dependent electronic and optical properties.

Interlayer interactions significantly influence bandgap and excitonic features.

Various engineering techniques can modulate the properties of black phosphorus.

Abstract

In 2D materials, the quantum confinement and van der Waals-type interlayer interactions largely govern the fundamental electronic and optical properties, and the dielectric screening plays a dominant role in the excitonic properties. This suggests strongly layer-dependent properties, and a central topic is to characterize and control the interlayer interactions in 2D materials and heterostructures. Black phosphorus is an emerging 2D semiconductor with unusually strong interlayer interactions and widely tunable direct bandgaps from the monolayer to the bulk, offering us an ideal platform to probe the layer-dependent properties and the crossover from 2D to 3D (i.e., the scaling effects). In this review, we present a comprehensive and thorough summary of the fundamental physical properties of black phosphorus, with a special focus on the layer-dependence characters, including the electronic band structures, optical absorption and photoluminescence, and excitonic properties, as well as the band structure engineering by means of electrical gating, strain, and electrochemical intercalation. Finally, we give an outlook for the future research.