GaN/Sc2CF2 heterostructure photodetector with exceptional polarization sensitivity

Abstract

This paper employs first-principles methods to compute the stability, electrical properties, and optical properties of the GaN/Sc₂CF₂ heterostructure and investigates its photoelectric effect by constructing a photodetector device. The GaN/Sc₂CF₂ heterostructure has been found to be an indirect bandgap semiconductor with a bandgap value of 1.836 eV, and its substantial stability has been determined through phonon spectrum and molecular dynamics calculations. A charge transfer occurs in the GaN/Sc₂CF₂ heterostructure, resulting in the formation of an internal electric field directed from the Sc₂CF₂ layer to the GaN layer. Compared to single-layer GaN and Sc₂CF₂, the GaN/Sc₂CF₂ heterostructure has a wider absorption spectrum and enhanced light absorption in the visible light range. For the GaN/Sc₂CF₂ photodetector, it exhibits high photocurrent and extinction ratio, demonstrating favorable photoresponse characteristics, and it is more sensitive to changes in the polarization angle along the armchair direction. This research provides theoretical basis and research ideas for the photogalvanic detection capability of GaN/Sc₂CF₂ van der Waals heterostructures, offering a promising candidate material for photodetectors.