Thin films of CaB2O4: Eu were deposited on glass substrates by spray pyrolysis. The abnormal reduction of Eu3+to Eu2+in as-grown thin films was found at the growth temperatures from 300 to 500°C. Blue cathodoluminescence was observed by annealing films in air, correlating with further abnormal reduction of Eu ions and crystallization of compounds. These phenomena were explained by an electron transfer mechanism. The chromaticity coordinates were x=0.193 and y =0.089 with a dominant wavelength of 455 nm. Our results indicate calcium borate doped with Eu is a blue phosphor at temperatures suitable for the use of glass substrates in flat panel applications.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)