TY - JOUR
T1 - Photoluminescence and Raman study of CdS-Al 2O 3 nanocomposite films prepared by sol-gel techniques
AU - Panda, S. K.
AU - Chakrabarti, S.
AU - Ganguly, A.
AU - Chaudhuri, S.
PY - 2005/12/1
Y1 - 2005/12/1
N2 - The optical and microstructural properties of CdS-Al 2O 3 nanocomposite (CdS-Al 2O 3 = 20:80 to 50:50) thin films synthesized by sol-gel techniques were studied. Optical transmission spectra indicated a marked blue shift of the absorption edge due to quantum confinement. Band gaps of CdS-Al 2O 3 nanocomposites were found to vary in the range 3.69-2.61 eV. The sizes of the nanocrystals, estimated from the blue shift (0.2-1.2 eV) of the absorption edges and transmission electron microscopy, were found to vary in the range 2.8-7.0 nm. X-ray diffraction studies showed reflections from (111), (200), (220), and (311) planes of CdS in the cubic phase. Microstructural characterization by high-resolution transmission electron microscope (HRTEM) indicated well crystallinity of the nanoparticles and lattice fringes supported the cubic phase of CdS. Raman spectroscopy was carried out for CdS-Al 2O 3 nanocomposites, which indicated a prominent peak at ∼299 cm -1. Significant changes in the peak position and intensity of the Raman peak were observed with varying the annealing temperature (373-573 K). Photoluminescence measurements indicated a prominent broad peak at ∼1.81 eV due to the surface defects in the CdS nanocrystallites. The present study revealed Al 2O 3 to be a good capping material for CdS nanoparticles.
AB - The optical and microstructural properties of CdS-Al 2O 3 nanocomposite (CdS-Al 2O 3 = 20:80 to 50:50) thin films synthesized by sol-gel techniques were studied. Optical transmission spectra indicated a marked blue shift of the absorption edge due to quantum confinement. Band gaps of CdS-Al 2O 3 nanocomposites were found to vary in the range 3.69-2.61 eV. The sizes of the nanocrystals, estimated from the blue shift (0.2-1.2 eV) of the absorption edges and transmission electron microscopy, were found to vary in the range 2.8-7.0 nm. X-ray diffraction studies showed reflections from (111), (200), (220), and (311) planes of CdS in the cubic phase. Microstructural characterization by high-resolution transmission electron microscope (HRTEM) indicated well crystallinity of the nanoparticles and lattice fringes supported the cubic phase of CdS. Raman spectroscopy was carried out for CdS-Al 2O 3 nanocomposites, which indicated a prominent peak at ∼299 cm -1. Significant changes in the peak position and intensity of the Raman peak were observed with varying the annealing temperature (373-573 K). Photoluminescence measurements indicated a prominent broad peak at ∼1.81 eV due to the surface defects in the CdS nanocrystallites. The present study revealed Al 2O 3 to be a good capping material for CdS nanoparticles.
KW - CdS-Al O nanocomposite
KW - Quantum confinement effect photoluminescence
KW - Raman study
KW - Sol-gel
UR - http://www.scopus.com/inward/record.url?scp=22844439679&partnerID=8YFLogxK
U2 - 10.1166/jnn.2005.068
DO - 10.1166/jnn.2005.068
M3 - Article
C2 - 15913256
AN - SCOPUS:22844439679
SN - 1533-4880
VL - 5
SP - 459
EP - 465
JO - Journal of Nanoscience and Nanotechnology
JF - Journal of Nanoscience and Nanotechnology
IS - 3
ER -