The blue-green emitting thin film electroluminescence SrS:Ce phosphor film was prepared by RF magnetron sputtering. The film was deposited on a-$Si_xN_y$/ITO/Glass in a mixed gas of 60% Ar and 40% He, at 200W, with 1at% Ce doped SrS target, taking the pressure and the temperature as variables of deposition. The crystallinity of the deposited film was investigated by measuring FWHM in XRD pattern, and the microstructure and the composition were analyzed by SEM, WDS, AES and RBS.
The SrS film deposited at 300℃ and 5mTorr shows the strong (200) preferred orientation. As the deposition temperature increased from RT to 450℃ the deposition rate, FWHM, and the lattice parameter decreased. The deposition rate shows the maximum at 5mTorr and FWHM increased when the deposition pressure varies from 0.5 to 10mTorr at 450℃. The composition of the film was $SrS_0.84$ showing the S deficiency and 10at% oxygen was involved. The TFEL device with the structure of Al/SiN/SrS:Ce/SiN/ITO/Glass was fabricated for luminescence test, but the test was failed owing to the low breakdown voltage of silicon nitride film used as the insulator layer.
