AbstractGa-doped ZnO layers were grown on sapphire substrates by molecular beam epitaxy (MBE). Low-temperature photoluminescence (PL) and room-temperature Raman spectra were investigated. Defect-related modes at 277 and 510 cm−1 appeared in the Raman spectrum for Ga-doped layers. The PL spectrum is dominated by a donor-bound exciton peak at 3.356 eV. A weak yellow luminescence (YL) band peaking at 2.1-2.2 eV was studied in detail. It shifted to higher photon energies (up to 0.1 eV) with increasing excitation intensity. The YL band is attributed to transitions from shallow donors to a deep acceptor. The acceptor is thought to be a Zn vacancy-related defect because the intensity of the YL band decreased dramatically with Ga doping.
Ga-doped Ca12Al14O33 mayenite oxide ion conductors: synthesis, defects, and electrical properties
