LI Zhi-qiang, TIAN Shao-hua, SONG Wei-peng, WEI Zhi-ren, DONE Guo-yi, DOU Jun-hong. Thermoluminescence of (Zn, Cd)S:Cu, Cl Luminescent Material[J]. Chinese Journal of Luminescence, 2005,26(3): 316-320
LI Zhi-qiang, TIAN Shao-hua, SONG Wei-peng, WEI Zhi-ren, DONE Guo-yi, DOU Jun-hong. Thermoluminescence of (Zn, Cd)S:Cu, Cl Luminescent Material[J]. Chinese Journal of Luminescence, 2005,26(3): 316-320DOI:
The direct bandgap semiconductor compound ZnS and CdS were used as multiple based material. The luminescent characteristic were changed by multibase. (Zn
Cd)S:Cu
Cl electroluminescent material specimens were prepared by adding 5%
7%
10%
15%
20% CdS in ZnS respectively.There were two obvious thermoluminescence peaks from -180℃ to -20℃ in the thermoluminescence curves of the five specimens. The concentration of CdS did not influence the category and the depth of the traps in the material
the temperature of peaks are -150℃ and -50℃. The concentration of CdS did not change the relative intensity of the thermoluminescence peak at -150℃ obviously
the relative intensity were 55.6
46.7
60.2
65.0 and 66.5 respectively
but changed the relative intensity of the thermoluminescence peak a t-50℃.The relative intensity increased with the concentration of CdS increased. When the Cd
2+
concentration was 5%
the peak of the curve was 7.1
when the Cd
2+
concentration was 7%
the peak of the curve was 13.4. When the Cd
2+
concentration was 10%
the peak of the curve was 32.4. When the Cd
2+
concentration was 15%
the peak of the curve increased to 82.2 quickly and when the Cd
2+
concentration was 20%
the peak of the curve forther increased to 97.6. The luminescence spectra of specimens moved from shortwave to longwave and the brightness descended as the concentration of CdS increased as shown by the measuring results of luminescence spectra and brightness. We therefore analyzed the result that excessive Cd
2+
caused the decline of luminance because the replacement of Zn
2+
by Cd
2+
in the crystal lattice introduced the defects
and sequently the defects caused the formation of radiationless center. The energy of trapped electrons by the radiationless recombination center turns into the radiationless transition
the phase which is disadvantageous to luminescence increases when the Cd
2+
replaces the Zn
2+
in the crystal lattice synchronously. The Cd
2+
replaces the Zn
2+
in the crystal lattice which results in the descending of the bottom of the conduction band
therefore decreases the forbidden band width of based material
which makes the luminescence spectrum moves from shortwave to longwave continuously.The thermoluminescence curves
luminescence spectrum and brightness changed accordingly as the concentration of CdS changed
which makes us find a way to obtain the (Zn
Cd)S:Cu
Cl powder electroluminescent material with the specific luminescence characteristic.