Portal de Periódicos da CAPES

Oxide coating for alkaline earth sulfide based phosphor

2003; Elsevier BV; Volume: 105; Issue: 2-4 Linguagem: Inglês

10.1016/s0022-2313(03)00117-0

1872-7883

Chongfeng Guo, Benli Chu, Mingmei Wu, Qiang Su,

Gas Sensing Nanomaterials and Sensors

An investigation is reported on the coating of the alkaline earth sulfide based red emitting phosphor Ca0.8Sr0.2S:Eu2+, Tm3+ by a thin layer of SiO2 or TiO2 using the sol–gel process. Their alkoxides were used as precursors and were dissolved in an aqueous ethanol medium. EDX (energy dispersive X-ray), SEM (scanning electron microscopy) and powder XRD (X-ray diffraction) were used to characterize the coating. The properties of coated phosphors were also tested; resistances of coated phosphors to moisture and other atmospheric components have been enhanced to a great degree without more loss of their optical properties. When the ratio of oxide ranges from 2% to 5% in weight, the brightness of phosphor has no remarkable change but the stability has been improved greatly.