Thin films of Sr2B5O9Cl: Eu were deposited on glass plates using spray pyrolysis of aqueous solutions. Films exhibited blue cathodoluminescence and photoluminescence, indicating the films contained Eu2+ rather than Eu3+. A luminance of 76 cd/m2 at 5 kV was obtained for annealed films on glass substrates. The chromaticity coordinates were x=0.162 and y=0.035 with a dominant wavelength of 450 nm and a 95% color purity. © 2001 American Institute of Physics.