No Cover Image

Journal article 23092 views 128 downloads

A first-principles theoretical study of the electronic and optical properties of twisted bilayer GaN structures

Xiang Cai, Shuo Deng, Lijie Li Orcid Logo, Ling Hao

Journal of Computational Electronics

Swansea University Authors: Xiang Cai, Lijie Li Orcid Logo

  • 54288.pdf

    PDF | Version of Record

    Released under the terms of a Creative Commons Attribution 4.0 International License (CC-BY).

    Download (1.62MB)

Abstract

Gallium nitride (GaN) is a well-investigated material that is applied in many advanced power electronic and optoelectronic devices due to its wide bandgap. However, derivatives of its monolayer form, such as bilayer structures, have rarely been reported. We study herein the electronic and optical pr...

Full description

Published in: Journal of Computational Electronics
ISSN: 1569-8025 1572-8137
Published: Springer Science and Business Media LLC 2020
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa54288
Tags: Add Tag
No Tags, Be the first to tag this record!
Abstract: Gallium nitride (GaN) is a well-investigated material that is applied in many advanced power electronic and optoelectronic devices due to its wide bandgap. However, derivatives of its monolayer form, such as bilayer structures, have rarely been reported. We study herein the electronic and optical properties of GaN bilayer structures that are rotated in the plane at several optimized angles by using the density functional theory method. To maintain the structural stability and use a small cell size, the twisting angles of the GaN bilayer structures are optimized to be 27.8°, 38.2°, and 46.8° using the crystal matching theory. The band-structure analysis reveals that the bandgap is wider for the twisted structures compared with the nontwisted case. The simulation results provide the absorption coefficient, extinction coefficient, reflectivity, and refractive index at these angles. The spectra of all these optical properties match with the bandgap values. The simulated refractive index of the bilayer structures at all the twisting angles including 0° is smaller than that of bulk GaN, indicating a reduced scattering loss for optoelectronics applications. Considering the results of this analysis, the possible applications may include low-loss integrated electronic and optical devices and systems.
Keywords: GaN bilayer; Twisting efect; Optical properties