Blue, green and red cathodoluminescence of Y2O3 phosphor films prepared byspray pyrolysis

Thin films of yttrium oxide doped separately with Eu3+, Tb3+ and Tm3+ were deposited by spray pyrolysis. The effect of preparation conditions on the s tructural and cathodoluminescent (CL) properties of the thin films was inve stigated. Films containing Eu3+, Tb3+ and Tm3+ emitted red, green and blue colors, respectively. Films of yttrium oxide doped with Tm were evaluated i n detail. The blue emission of these films had CIE chromaticity coordinates of x = 0.158 and y = 0.150 with a dominant wavelength of 476 nm and a colo r purity of 78% compared to CIE Standard Source C. The CL intensity of the films under 5 kV beam excitation and a current density of 5 mA/cm(2) depend ed strongly on annealing conditions and thulium doping concentration. For T m-doped films the maximum luminance was 30.4 cd/m(2) and there was a linear relationship between the CL intensity and excitation voltage. A luminance of 255 cd/m(2) was obtained for the Eu-doped film. The dominant wavelength was 604 nm with 100% purity, and x = 0.645 and y = 0.357. The luminance for the Tb-doped film was 72 cd/m(2) with a dominant wavelength of 547 nm and 77% purity. (C) 2001 Elsevier Science B.V. All rights reserved.