TY - JOUR
T1 - Microstructure and electroluminescence of ZnS:Cu,Cl phosphor powders prepared by firing with CuS nanocrystallites
AU - Nien, Yung Tang
AU - Chen, In Gann
AU - Hwang, Chii Shyang
AU - Chu, Sheng Yuan
N1 - Funding Information:
Acknowledgments This work was supported under projects from the National Science Council (NSC 91-2622-E-006-059-CC3 and NSC-92-2622-E-006-129-CC3) of Taiwan. The author (Y.T. Nien) also thanks the Center for Micro/Nano Technology Research, National Cheng-Kung University, Taiwan, for providing student scholarship and their support in TEM sample preparation.
PY - 2006/12
Y1 - 2006/12
N2 - This paper presents the microstructure and electroluminescent performance of ZnS:Cu,Cl phosphor powders prepared by firing micrometer-sized ZnS with NaCl and CuS nanocrystallites at 900°C in the reducing atmosphere. A series of samples with Cu addition ranging from 40 to 5000 ppm were studied. XRD analysis showed that ZnS:Cu,Cl samples with Cu addition of ∼400 ppm exhibited a transformation from hexagonal to cubic structure. The whole series of ZnS:Cu,Cl samples showed significant photoluminescent (PL) intensity; however, only samples with Cu addition of ∼400 ppm revealed measurable electroluminescent (EL) intensity. This difference was supposed to be a result of nano-sized CuxS precipitation in ZnS during firing treatment, where Cu xS acted as electron emission source to enhance the EL intensity. Furthermore, ZnS:Cu,Cl powder sections were analyzed using X-ray mapping (XRM) of a scanning transmission electron microscope, revealing that CuxS precipitates of 50-80 nm in size were observed only in the samples with EL emission, i.e. Cu addition ∼400 ppm. The variation of EL intensity was interpreted in terms of the concentration of Cu activators as well as the phase and the amount of CuxS in ZnS.
AB - This paper presents the microstructure and electroluminescent performance of ZnS:Cu,Cl phosphor powders prepared by firing micrometer-sized ZnS with NaCl and CuS nanocrystallites at 900°C in the reducing atmosphere. A series of samples with Cu addition ranging from 40 to 5000 ppm were studied. XRD analysis showed that ZnS:Cu,Cl samples with Cu addition of ∼400 ppm exhibited a transformation from hexagonal to cubic structure. The whole series of ZnS:Cu,Cl samples showed significant photoluminescent (PL) intensity; however, only samples with Cu addition of ∼400 ppm revealed measurable electroluminescent (EL) intensity. This difference was supposed to be a result of nano-sized CuxS precipitation in ZnS during firing treatment, where Cu xS acted as electron emission source to enhance the EL intensity. Furthermore, ZnS:Cu,Cl powder sections were analyzed using X-ray mapping (XRM) of a scanning transmission electron microscope, revealing that CuxS precipitates of 50-80 nm in size were observed only in the samples with EL emission, i.e. Cu addition ∼400 ppm. The variation of EL intensity was interpreted in terms of the concentration of Cu activators as well as the phase and the amount of CuxS in ZnS.
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U2 - 10.1007/s10832-006-8913-5
DO - 10.1007/s10832-006-8913-5
M3 - Article
AN - SCOPUS:33847209295
VL - 17
SP - 299
EP - 303
JO - Journal of Electroceramics
JF - Journal of Electroceramics
SN - 1385-3449
IS - 2-4
ER -