Luminescent properties of blue-emitting SrS:Cu, F thin-film EL devices

SrS: Cu, F thin-film electroluminescent (TFEL) devices were prepared by electron beam evaporation and their luminescent properties were investigated. Photoluminescence (PL) spectra of SrS: Cu, F phosphors were measured under excitation with 325 nm of He-Cd laser at room temperature. It was shown that the PL spectra for Cu concentration of 0.3 at% showed a strong blue emission with the peak at about 470 nm. A standard double insulator structure was employed for EL device fabrication using Y2O3 as first and second insulators, and ZnS was employed as buffer layer. TFEL devices prepared with rapid thermal annealing at 900 degreesC showed the same blue emission as the PL spectrum. The maximum luminance of 82 cd/m(2) and CIE coordinates of (x = 0.13 y = 0.22) could be obtained for devices with Cu content of 0.3 at% driven by 1 kHz pulses.