Correlation of a generation-recombination center with a deep level trap in GaN

We report on the identification of a deep level trap centre which contributes to generation-recombination noise. A n-GaN epilayer, grown by MOCVD on sapphire, was measured by deep level transient spectroscopy (DLTS) and noise spectroscopy. DLTS found 3 well documented deep levels at E-c - 0.26 eV, E-c - 0.59 eV, and E-c - 0.71 eV. The noise spectroscopy identified a generation recombination centre at E-c - 0.6 +/- 60.1 eV with a recombination lifetime of 65 mu s at 300 K. This level is considered to be the same as the one at E-c - 0.59 eV measured from DLTS, as they have similar trap densities and capture cross section. This result shows that some deep levels contribute to noise generation in GaN materials. (C) 2015 AIP Publishing LLC.