Ho^(3+)对CaGa_2S_4:Eu^(2+)发光性能的影响

Effect of Ho^(3+) Ion on Luminescent Property of CaGa_2S_4:Eu^(2+)

研究了二价铕离子与三价钬离子共同掺杂的荧光体CaGa2S4∶Eu2+(0.5%),Ho3+(1 0%)的荧光、三维热释发光及其长余辉发光特性。作为对比,同时研究了CaGa2S4∶Eu2+(0.5%)及CaGa2S4∶Ho3+(1 0%)的荧光和三维热释发光性质,发现CaGa2S4∶Eu2+(0.5%),Ho3+(1 0%)的发射波长为552nm的黄绿色余辉长达40min,CaGa2S4∶Eu2+(0.5%)不具有长余辉,而CaGa2S4∶Ho3+(1.0%)具有很弱的余辉。热释光及其三维图谱的研究表明,由于Ho3+的引入而产生了一个新的陷阱能级,从而使CaGa2S4∶Eu2+(0.5%),Ho3+(1.0%)具有长余辉的发光特性。

The afterglow luminescent property and thermo-luminescence (TL) of CaGa_2S_4∶Eu^(2+), Ho^(3+) were systematcally investigated. The afterglow of Eu and Ho Co-doped CaGa_2S_4 shows a broadband emission at 552 nm, which is the same as that of Eu doped CaGa_2S_4 only. And the decay behavior of CaGa_2S_4∶Eu^(2+), Ho^(3+) was investigated, which shows that (CaGa_2S_4∶)Eu^(2+),Ho^(3+) is a phosphor with long afterglow, whereas the CaGa_2S_4∶Eu^(2+) is a phosphor without long afterglow. Comparison of TL curves and 3D-TL emission spectra of CaGa_2S_4∶Eu^(2+), Ho^(3+) and CaGa_2S_4∶Eu^(2+) show that a new trap center is produced at about 80 ℃, which is the basic reason of CaGa_2S_4∶Eu^(2+), Ho^(3+) with long afterglow.