Abstract
projection TVs have been manufactured as home used displays with large screen. The development to achieve the thinner phosphor screen and the higher density of electron beam will realize the high resolution in projection tubes (PRTs). However, the life time and the luminous efficiency of many phosphors decrease as these techniques make the excitation density increase. Especially, blue ZuS:Ag, Al phosphor in PRTs has a problem of the luminous saturation. Blue ZnS:Ag, Al phosphor for PRTs was prepared by gas flow synthesis and its traps were estimated by a thermoluminescence (TL) curves and its luminance were measured under a cathode-ray excitation. In TL curves, TL peak was observed at around 430K. In the synthesis with increasing the H2S flow rate, the deep trap decreased drastically. And its luminance went up to 5% higher than that prepared by a flux synthesis. It is clear that the deep trap density associated with sulfur vacancies is closely related to the luminous saturation and it will be a candidate for an Auger trap center.
