Takeru Okada

This study demonstrates the formation of ZnWO4/WO3 composite that are engendered by cosputtering deposition followed by calcination. The concentrations of the tungsten dopant are found to have a profound effect on crystal formation, composition, and photoluminescence. The quantum efficiency measurements investigating different excitation light directions indicate that WO3 can form an underlayer of ZnWO4 at high dopant concentrations. The formation of bilayerlike films is caused by segregation, resulting from time evolution of sputtering yield due to temperature changes at the surface of the sputtering target.