Effect on reliability and thermal stability of Ba x Sr 2−x SiO 4 :Eu 2+ phosphor film for LED applications

Europium doping strontium silicate barium phosphors [Ba x Sr 2−x SiO 4 :0.02Eu 2+ (x = 0, 0.2, 0.5, 0.8, 1, 1.5 and 2)] were successfully prepared by conventional solid-state reaction technology, and the phosphor films are prepared from the synthesized Ba x Sr 2−x SiO 4 :0.02Eu 2+ (x = 0, 0.2, 0.5, 0.8, 1, 1.5 and 2) phosphors by a simple spin coating methods. The influence of different content of Ba 2+ doping on the photoluminescence (PL) spectra, thermal stability and reliability of prepared Ba x Sr 2−x SiO 4 :0.02Eu 2+ (x = 0, 0.5, 1, 1.5 and 2) phosphors and phosphor films were investigated. As Ba 2+ concentration increased from 0 to 2, the photoluminescence spectra peaks of phosphor shifted from 570 to 511 nm and the photoluminescence spectra peaks of phosphor films shifted from 568 to 513 nm under the excitation of 460 nm. It can be summarized that the increase of Ba concentration increased the thermal stability (improve about 30%) and enhanced the reliability (improve about 7%) largely when the x value is x is not greater than 1, whether it is phosphor or film. However, it seems that phosphor and phosphor films couldn’t improve with the increase of Ba 2+ after the xenon lamp aging test. What is more, the three kinds of experiments show that the Ba x Sr 2−x SiO 4 :0.02Eu 2+ phosphor films with different Ba 2+ concentration have better reliability (improve about 10%) than the Ba x Sr 2−x SiO 4 :0.02Eu 2+ phosphors with different Ba 2+ concentration.