scholarly journals Effect of Nickel Doping on Optical Properties of CdS Nanoparticles Synthesized via. Co-precipitation Technique

2017 ◽  
Vol 14 (1) ◽  
pp. 05-08 ◽  
Author(s):  
Suresh Kumar ◽  
J. K Sharma

This work presents a comprehensive study on the optical behavior of cadmium sulphide (CdS) nanoparticles under the effect of nickel (Ni2+ ions) doping. The pristine and Ni-doped CdS nanoparticles (CdS:Ni) have been synthesized via. conventional co-precipitation technique and analyzed using UV-visible spectrophotometer. Ni2+ ions with different concentrations (2% and 4%) incorporate in CdS structure, modify it and hence, exhibit a red shift of absorption edge. The increase in Ni2+ ions concentration from 0% to 4% leads to tailor the optical band gap of CdS from 2.70 eV to 2.47 eV. These band gap values are higher than that of bulk CdS which confirm a quantum size effect in the synthesized nanoparticles.

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Damian C. Onwudiwe ◽  
Madalina Hrubaru ◽  
Eno E. Ebenso

The thermal decomposition of bis(N,N-diallyldithiocarbamato)Cd(II) in a “one-pot” synthesis in tri-n-octylphosphine oxide (TOPO) and hexadecylamine (HDA) afforded CdS (TOPO-CdS and HDA-CdS) of varying optical properties and morphologies. The influence of the ratio of the precursor concentration to the capping molecule, as a factor affecting the morphology and size of the nanoparticles, was investigated. The particles varied in shape from spheres to rods and show quantum size effects in their optical spectra with clear differences in the photoluminescence (PL) spectra. The PL spectrum of the HDA capped CdS nanoparticles has an emission maximum centred at 468, 472, and 484 nm for the precursor to HDA concentration ratio of 1 : 10, 1 : 15, and 1 : 20, respectively, while the TOPO capped nanoparticles show emission peaks at 483, 494, and 498 nm at the same concentration ratio. Powdered X-ray diffraction (p-XRD) shows the nanoparticles to be hexagonal. The crystallinity of the nanoparticles was evident from high resolution transmission electron microscopy (HRTEM) which gave well-defined images of particles with clear lattice fringes.


2008 ◽  
Vol 3 ◽  
pp. 97-102 ◽  
Author(s):  
Dinu Patidar ◽  
K.S. Rathore ◽  
N.S. Saxena ◽  
Kananbala Sharma ◽  
T.P. Sharma

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.


2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.


2020 ◽  
pp. 44-52
Author(s):  
Ahmed Ahmed S. Abed ◽  
Sattar J. Kasim ◽  
Abbas F. Abbas

In the present study, the microwave heating method was used to prepare cadmium sulfide quantum dots CdSQDs films. CdS nanoparticles size average obtained as (7nm). The morphology, structure and composition of prepared CdSQDs were examined using (FE-SEM), (XRD) and (EDX). Optical properties of CdSQDs thin films formed and deposited onto glass substrates have been studied at room temperature using UV/ Visible spectrophotometer within the wavelength of (300-800nm), and Photoluminescence (PL) spectrum. The optical energy gap (Eg) which estimated using Tauc relation was equal (2.6eV). Prepared CdS nanoparticles thin films are free from cracks, pinholes and have high adhesion to substrate.


2013 ◽  
Vol 1493 ◽  
pp. 281-286
Author(s):  
Keisuke Yoshimura ◽  
Tetsuya Hashimoto ◽  
Hiroshi Katsumata

ABSTRACTOptical band-gap and cathode luminescence (CL) properties of anatase TiO2 nanopowders mixed with γ- Al2O3 powders by planetary ball mill were evaluated as a function of a powder mass ratio (x=Al2O3/TiO2) of 0 to 0.5 and their correlation with XRD spectra was also investigated. The optical band-gap of TiO2 increased from 3.36 eV to 3.41eV with increasing milling time (tm) up to 600 min, which was in good agreement with the blue shifts observed in the CL spectra with increasing tm and it was interpreted as a quantum size effect. In addition, the optical band-gap of TiO2 powders mixed with Al2O3 with tm=60min greatly increased from 3.36 eV to 3.48 eV with increasing x up to x=0.5. On the other hand, the optical band-gap of all the powders was decreased by annealing at temperatures above 600°C, which was evidenced by the XRD spectra to be due to the growth of grain size.


1991 ◽  
Vol 256 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Hideki Koyama

ABSTRACTThe optoelectronic properties of porous Si (PS) are presented in terms of electroluminescence (EL), photoluminescence (PL), photoconduction (PC), and optical absorption. Observations of injection-type EL, efficient PL, band-gap widening, and photosensitivities In the visible region are consistent with the quantum size effect model in PS.


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