Metastability from Photoluminescence of n-type GaN

TL;DR

This study investigates the metastability in unintentionally doped GaN through temperature-dependent photoluminescence, revealing the role of oxygen impurities and providing reaction energies for shallow-deep donor transitions.

Contribution

It offers new insights into the origin of DX centers in GaN, suggesting oxygen impurities as the cause rather than silicon, and quantifies reaction energies for impurity transitions.

Findings

Reaction energy U of donor atom is 0.1 eV.

Shallow donors are more stable than deep centers.

Oxygen impurities likely cause DX centers in GaN.

Abstract

We measured the temperature dependence of photoluminescence involved with the metastability of unintentionally doped GaN. Reaction energy U of donor atom is 0.1eV and shallow donor is more stable than deep center. The impurity transition was applied to unintentionally doped GaN at low temperature and reaction energy U was provided for shallow-deep transition. We propose that the origin of DX center in unintentionally doped wurtize GaN is considered to be an oxygen impurity instead of silicon.