Time-resolved spectroscopy of Zn- and Cd-doped GaN

Abstract

Photoluminescence transients and time-resolved luminescence spectra are reported for the violet-blue emissions from epitaxial layers of Zn- and Cd-doped GaN. A typical decay time of 300 ns is reported for the blue GaN:Zn emission, peaking at about 2.89 eV. For GaN:Cd a somewhat longer decay time of τ≊1 μs dominates for the broad peak centered at ≊2.72 eV. In both cases it is concluded that the simple process involving a free-to-bound transition of an electron to a hole bound at the ZnGa, respectively, the CdGa acceptor is the dominating recombination mechanism corresponding to these characteristic decay rates.