Correlation between structural changes and luminescent properties of ZnMgS:Mn thin film phosphor with annealing temperature

Abstract

With varying rapid thermal annealing temperature, luminescent properties of Zn 0.75 Mg 0.25 S :Mn thin film deposited by RF-magnetron sputtering technique were investigated. Although all samples were deposited from identical source composition, it was found that a main peak wavelength of photoluminescence of Zn 0.75 Mg 0.25 S :Mn depended on RTA temperatures and it shifted toward shorter wavelength upon the increase of RTA temperature. The same dependence of wavelength on RTA temperature was also observed in cathodoluminescence as well as electroluminescence measurements. It is noticeable that Zn 0.75 Mg 0.25 S :Mn thin film phosphor in this study showed more reddish emission than those of the previous studies. It was revealed that changes of the luminescent properties were originated from structural changes in Zn 0.75 Mg 0.25 S :Mn thin film phosphor from cubic to hexagonal phases using X-ray pole figure mapping, and the growing up of hexagonal phase mainly caused cracks and porous morphology on the surface of thin films. It is suggested that the phase transition would be the origin of luminescent property changes with respect to rapid thermal annealing temperature.