Abstract The study of energy transfer mechanism from different capping agents to intrinsic luminescent vacancy centres of zinc sulphide
(ZnS) has been reported in the present work. Nanoparticles of capped and uncapped ZnS are prepared by co-precipitation reaction.
These nanoparticles are sterically stabilized using organic polymers—poly vinyl pyrrolidone, 2-mercaptoethanol and thioglycerol.
Monodispersed nanoparticles were observed under TEM for both capped and uncapped ZnS nanopowders. However, for uncapped ZnS
nanopowders, tendency for formation of nanorod like structure exists. Size of ZnS crystallites was calculated from X-ray diffraction
pattern. The primary crystallite size estimated from X-ray diffraction pattern is 1.95–2.20 nm for capped nanostructures and
2.2 nm for uncapped nanostructures. FTIR spectra were conducted to confirm capping. Zeta potential measurements have been
done to check the stability of dispersed nanoparticles. Band gap measurement was done by UV–visible spectrophotometer. Excitation
and emission spectra are also performed in order to compare optical properties in various samples. Increase in emission intensity
and band gap has been observed by adding different capping agents in comparison to uncapped ZnS nanoparticles. The results
show that in capped ZnS nanoparticles the mechanism of energy transfer from capping layer to photoluminescent vacancy centres
is more pronounced.
(ZnS) has been reported in the present work. Nanoparticles of capped and uncapped ZnS are prepared by co-precipitation reaction.
These nanoparticles are sterically stabilized using organic polymers—poly vinyl pyrrolidone, 2-mercaptoethanol and thioglycerol.
Monodispersed nanoparticles were observed under TEM for both capped and uncapped ZnS nanopowders. However, for uncapped ZnS
nanopowders, tendency for formation of nanorod like structure exists. Size of ZnS crystallites was calculated from X-ray diffraction
pattern. The primary crystallite size estimated from X-ray diffraction pattern is 1.95–2.20 nm for capped nanostructures and
2.2 nm for uncapped nanostructures. FTIR spectra were conducted to confirm capping. Zeta potential measurements have been
done to check the stability of dispersed nanoparticles. Band gap measurement was done by UV–visible spectrophotometer. Excitation
and emission spectra are also performed in order to compare optical properties in various samples. Increase in emission intensity
and band gap has been observed by adding different capping agents in comparison to uncapped ZnS nanoparticles. The results
show that in capped ZnS nanoparticles the mechanism of energy transfer from capping layer to photoluminescent vacancy centres
is more pronounced.
- Content Type Journal Article
- Category Research Paper
- DOI 10.1007/s11051-009-9844-2
- Authors
- Manoj Sharma, Thapar University School of Physics and Materials Science Patiala 147 004 Punjab India
- Sunil Kumar, Maharishi Markandeshwar University Department of Physics Mullana, Ambala 133 203 India
- O. P. Pandey, Thapar University School of Physics and Materials Science Patiala 147 004 Punjab India
- Journal Journal of Nanoparticle Research
- Online ISSN 1572-896X
- Print ISSN 1388-0764
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