White Light Emission from ZnS:Mn Thin Films Deposited on GaN Substrates by Pulsed Laser Deposition**Supported by the Science and Technology Plan Projects of Colleges and Universities in Shandong Province under Grant No J15LN33, the Scientific Research Foundation of Binzhou University under Grant No BZXYG1512, and the Doctoral Scientific Research Foundation of Binzhou University under Grant No 2014Y15.

Abstract

ZnS:Mn thin films are grown on GaN substrates by pulsed laser deposition. The structure, morphology and optical properties are investigated by x-ray diffraction, scanning electron microscopy and photoluminescence (PL). The obtained ZnS:Mn thin films are grown in preferred orientation along β-ZnS (111) direction corresponding to crystalline structure of cubic phase. The deposition temperature has an obvious effect on the structure, surface morphology and optical properties of ZnS:Mn thin films. PL measurements show that there are two emission bands located at 440 nm and 595 nm when the films are deposited at temperatures from 100°C to 500°C. The relative integrated intensity of the blue emission and orange-red emission is determined by the deposition conditions. At the proper deposition temperature of 300°C, the color coordinate is closest to (0.33, 0.33). The ZnS:Mn films on GaN substrates can exhibit white light emission.