Stacking defects in GaP nanowires: Electronic structure and optical properties

TL;DR

This study investigates how twin boundaries and stacking faults in GaP nanowires influence their electronic and optical properties, revealing potential impacts on device efficiency through combined ab initio simulations and experiments.

Contribution

It provides new insights into the effects of planar defects on GaP nanowires' properties using a novel combination of simulation and experimental methods.

Findings

Twin boundaries act as atomically narrow wurtzite phases with type-I band alignment.

Stacking faults introduce shallow trap states affecting optical properties.

Defects significantly impact nanowire device performance.

Abstract

Formation of twin boundaries during the growth of semiconductor nanowires is very common. However, the effects of such planar defects on the electronic and optical properties of nanowires are not very well understood. Here, we use a combination of ab initio simulation and experimental techniques to study these effects. Twin boundaries in GaP are shown to act as an atomically-narrow plane of wurtzite phase with a type-I homostructure band alignment. Twin boundaries and stacking faults (wider regions of the wurtzite phase) lead to the introduction of shallow trap states observed in photoluminescence studies. These effects should have a profound impact on the efficiency of nanowire-based devices.