Original scientific paper
Synthesis, Structural and Optical Properties of PVP Encapsulated CdS Nanoparticles
L. Saravanan
; Centre for Nanoscience and Technology, Anna University, India
S. Diwakar
; Department of Physics, Presidency College, India
A. Pandurangan
; Institute of Catalysis and Petroleum Technology, Anna University, Indi
R. Jayavel
; Centre for Nanoscience and Technology, Anna University, India
Abstract
Highly monodispersed CdS nanoparticles using
polyvinyl pyrrolidone (PVP) as the capping agent were
synthesised by chemical coprecipitation method. The
surface‐modified cadmium sulfide nanoparticles were
found to be remarkably stable. In the presence of PVP,
cubic phase with small grain size of CdS were observed in
XRD. The peaks were identified to originate from (111),
(220) and (311) planes of CdS, respectively. The crystallite
size of the synthesised CdS nanoparticles was about 3 nm
calculated from the (111) plane of XRD pattern and it was
also confirmed through HRTEM. Morphology and
elemental mapping of the synthesised nanoparticles were
studied by SEM and EDX analyses. Increase in the band
gap with decrease in the particle size was observed from
the reflectance mode UV spectrum, which confirms the
quantum confinement effect. From the photoluminescence
studies, enhanced near‐band‐edge blue light emission and
significantly reduced defect‐related green emission were
observed. Longitudinal optical (LO) phonon modes,
corresponds to pure CdS were observed in Raman
spectrum.
Keywords
PVP capping; CdS nanoparticles; HRTEM; FTIR; Photoluminescence; Raman spectra
Hrčak ID:
76916
URI
Publication date:
15.9.2011.
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