Development of blue-emitting SrSe:Ce thin-film electroluminescent devices

The development of electroluminescent (EL) materials of red, green and blue colours is essential for the realization of full colour EL display devices. In such a current status, SrSe thin films doped with Ce have been prepared by a multi-source deposition technique, and their luminescent properties have been investigated in order to develop blue-emitting SrSe:Ce thin-film electroluminescent (TFEL) devices with good chromaticity. The quality of the films is influenced by the ratios of Sr to Se atoms arriving at the substrates. When the ratio is kept at 1:3, stoichiometric SrSe film is formed. The structural property depends on the substrate temperature. The SrSe films prepared at temperatures lower than 673 K indicate to be [100]-oriented and the orientation deteriorates gradually at higher temperature than 673 K. The crystallinity, on the other hand, becomes better with increasing the substrate temperature. Both photoluminescent and electroluminescent spectra of SrSe:Ce and its EL device demonstrate a blue emission with the intensity peak at about 470 nm; these spectra shift toward longer wavelength with increasing Ce concentration. (author). 11 refs., 12 figs., 1 tab