Sputtered Zn1−xGa2O4:Mn thin-film electroluminescent devices prepared using cadmium-assisted processing

Incorporating cadmium in the sputtering targets used to grow green-emitting zinc gallate doped with manganese is found to provide improvements in crystallinity, photoluminesience (PL), and electroluminescence (EL) performance, while reducing the annealing temperature requirements. It is shown that as-grown thin films do contain cadmium. The cadmium is then lost during thin-film annealing. The effect of cadmium is interpreted as an enhancement in vacancy concentration during the thin-film annealing process, which improves crystallinity, EL, and PL. X-ray diffraction and microscopy results are carefully studied and discussed.