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Indian Journal of Engineering and Materials Sciences (IJEMS) >
IJEMS Vol.11 [2004] >
IJEMS Vol.11(2) [April 2004] >
| Title: | Laser-induced phosphorescence studies of doubly-doped CaS phosphors |
| Authors: | Bhatti, H S
Sharma, Rajesh
Verma, N K
Kumar, Sunil |
| Issue Date: | Apr-2004 |
| Publisher: | CSIR |
| IPC Code: | Int. Cl.7 C 09 K 11/60; C 09 K 11/84 |
| Abstract: | Effect of killer impurities (Fe,
Co and Ni) on excited state life-times in CaS phosphors, doped with copper and
having variable concentrations of iron, cobalt and nickel has been studied in
this paper. The phosphors have been synthesized, and, then using a nitrogen
laser as the excitation source, their decay-curve analysis has been done.
Various strong emissions have been detected and the corresponding excited state
life-time values measured. These studies
are conducted at room temperature. Very interesting results are obtained with
the addition of killer impurities in the phosphors with single impurity. Life-time
values found to decrease appreciably with the addition of killer impurities (at
lower concentration) in the singly doped phosphors. These studies are important
as the excited state life-time of the sulphide phosphors prepared by flux
method converge to the longer side only, but with the addition of killer impurities
at a particular concentration, values of the life-times decreases up to large
extent. At higher concentration of killer impurities deeper traps contribute to
the phosphorescence, leading to the much higher increase in life-time values. |
| Page(s): | 121-124 |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Source: | IJEMS Vol.11(2) [April 2004]
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