Cathodoluminescence from Thin Film Zn[sub 2]GeO[sub 4]:Mn Phosphor Grown by Pulsed Laser Deposition

Low voltage cathodoluminescent (CL) characteristics of thin-film phosphors grown by pulsed laser deposition were investigated. The effects of substrate heating (600-750°C) and substrate type (MgO, Si, and yttria-stabilized zirconia) on the cathodoluminescent properties were studied. A characteristic green emission peak at 540 nm was observed at substrate temperatures of 650, 700, or 750°C. However, the emission was red shifted to 650 nm for a substrate temperature of 600°C. The red shift in emission wavelengths from 540 to 650 nm was attributed to a change in ionic state of the activator from to While the spectral position was independent of substrate type, the relative intensities of the cathodoluminescent emission peak varied with both substrate type as well as substrate temperature. At a substrate temperature of 600°C, the crystal structure of the film was mixed polycrystalline and amorphous. However, at substrate temperatures ranging from 650-750°C, the films were only polycrystalline with varying degrees of crystallinity that correlated with the CL intensity.