title: [Cathodoluminescent characteristics of green-emitting ZnAl2O4:Mn thin film phosphors].
abstract: Green electroluminescence was obtained from thin films of ZnAl2O4: Mn prepared by rf magnetron sputtering onto thick insulating ceramic sheets. Photoluminescence and stress-stimulated luminescence was obtained for Mn-doped ZnAl2O4 powder synthesized by the solid phase reaction. Since it is extremely stable chemically and thermally, ZnAl2O4 may emerge as an alternative choice to sulphide-based phosphors. In the present paper, thin films of ZnAl2O4: Mn were grown on aluminosilicate ceramic plates using spray pyrolysis of aqueous solutions. The cathodoluminescence (CL) properties of the films under low to medium excitation voltage (<5 kV) were investigated. The films exhibited green CL after being annealed at temperatures above 550 degrees C, which corresponds to the transition between 4 T1 and (6)A1 of Mn2+ ions located in the tetra coordination of the Zn2+ site in the spinel structure. The chromaticity coordinates were x = 0.150 and y = 0.734 with a dominant wavelength of 525 nm and an 82% color purity. The CL luminance and efficiency depended on the excitation voltage and current density. Saturation effects were observed as the current density increased. A luminance of 540 cd x m(-2) and an efficiency of 4.5 lm x W(-1) were obtained at an excitation voltage of 4 kV with a current density of 38 microA x cm(-2).
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing 100044, China. zhdlou@bjtu.edu.cn
authors.forename: Zhi-dong
authors.initials: ZD
authors.lastname: Lou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.forename: Lan-jie
authors.initials: LJ
authors.lastname: Yi
authors.forename: Sheng-yi
authors.initials: SY
authors.lastname: Yang