Abstract
SrS:Ce thin film electroluminescent(TFEL)devices have been prepared with codoping Zn as compensator for Sr vacancies and Na as charge compensator for Ce^<3+> centers. For the concentration of both Ce and Na of 0.2 mol%, Na acts as a flux and reduces the defects in SrS lattices, and gives rise to the blue shift of the PL and EL emission. BY increasing the concentration of Ce and Na above 0.4mol%, the Ce^<3+> emission shifts to further bluer due to decrease of Ce^<3+> centers. The limitation of the Ce^<3+> concentration in the SrS lattices having perfection improved by Zn and Na codoping has been found to be less than 0.2mol%.
