SrS:Ce transparent thin film electroluminescent (EL) devices having a glass substrate and both-sides transparent ITO electrodes have been prepared by electron beam evaporation method. A luminance and EL efficiency increase with increase of H{sub}2S supply, however, a blue color purity rather become worse. Sr vacancies, which tend to be generated in a excess sulfur atmosphere, promote incorporation of Ce into SrS lattice, and give rise to increase the luminance and efficiency. By the post deposition annealing, symmetry of current waveform for both applied voltage polarity is improved. The luminance is decreased to 80 of the initial value by a 16 h aging at 1 kHz. It is thought that the degradation is caused by change of Ce{sup}(3+) to nonradiative centers.
展开▼
