Electronic and Optical Properties of Functionalized GaN (10-10) Surfaces using Hybrid-Density Functionals

TL;DR

This study uses hybrid-density functional theory to analyze how small ligands, especially thiol groups, modify the electronic and optical properties of GaN (10-10) surfaces, with implications for biosensing and optoelectronic applications.

Contribution

It provides detailed theoretical insights into how ligand adsorption affects GaN surface electronic states, highlighting the limited optical activity of thiol-induced states on perfect surfaces.

Findings

Thiol groups introduce states into the GaN band gap.

These states are not optically active on perfect surfaces.

More realistic surface models are needed for practical applications.

Abstract

Adsorption of small ligands on semiconductor surfaces is a possible route to modify these surfaces so that they can be used in biosensing and optoelectronic devices. In this work we perform density-functional theory calculations of electronic and optical properties of small ligands on GaN-(10$\bar1$0) surfaces. From the investigated anchor groups we show that thiol groups introduce states into the GaN band gap. However, these state are not optically active, at least for these perfect surfaces. This means that more realistic surfaces need to be considered to suggest how surface modification can enhance the optical properties of GaN non-polar surfaces.