Optical properties of Cd_1 xZn_xS nanocrystallites in sol gel silica matrix

Abstract

Cd1−xZnxS nanoparticles with different compositions (0⩽x⩽1) embedded in silica matrix were prepared in thin film form by the sol–gel technique. The film texture and structural transformation with increasing x value were studied from transmission electron micrographs and electron diffraction patterns. Optical study indicated increase in optical bandgap and decrease in refractive index with increasing zinc content (x value). Photoluminescence studies showed emission from surface states with emission energy blue shifted with increasing zinc content in the films. Annealing behaviour of the films with increasing annealing temperature and time was studied.

The Energy Levels Splitting Calculated for Electrons in a Double Cd_1-XZn_xs Quantum Dot

“…Since several decades, films of Cd 1−x Zn x S have been widely applied in many useful devices particularly as window materials for fabricating p-n junctions [1][2][3][4][5][6][7][8][9][10]. On the subject of Cd 1-x Zn x S quantum dots (QDs), their technological potentialities have been demonstrated.…”

The Energy Levels Splitting Calculated for the Heavy and Light Holes in a Cd<sub>1-x</sub>Zn<sub>x</sub>S Double Quantum Dot

“…This is principally due to their utility as window materials in heterojunction solar cells with a p-type absorber such as CuInSe 2 , CuIn x Ga 1-x Se 2 or CuSnS z Se 1-z [4][5][6][7][8][9].…”

Compositional evolution and surface-related phenomena effects in ZnS–SiO2 nanocomposite films

“…The increase in band gap with decrease in particle size is the most identified aspect of quantum confinement in semiconductors leads to fascinating properties [8][9][10]. In recent years, the silica-based nanocomposites are regarded as one of the most attractive system for the quantum confinement of semiconductor nanocrystallites, for a better control of morphology (shape and size) and physical properties [11][12][13][14][15][16][17]. Silica has been recognized as one of the most efficient materials to improve mechanical stability (adhesion and corrosion resistance), thermal stability and PL intensity of ZnS nanoparticles [11,14,15,[18][19][20][21].…”

“…Besides, the silica matrix can act as a capping agent for tuning the optical band gap and refractive index of semiconductor nanoparticles to reach the functional application in optoelectronic devices [22,23]. ZnS-SiO 2 nanocomposite thin films can be deposited by several methods such as sputtering [24], spark plasma sintering (SPS) [25], ion implantation [26], vapor deposition [27] and sol-gel technique [2,[11][12][13]28]. Among the conventional methods, the sol-gel technique turns out more interesting in preparing nanoparticles dispersed in different matrices because it is economical saving deposition method provides a facilitated route to control composition stoichiometry, size and morphology of nanoparticles [29].…”