scholarly journals Impact of Aluminum Oxide Content on the Structural and Optical Properties of ZnO: AlO Thin Films

2021 ◽  
Vol 19 (51) ◽  
pp. 41-53
Author(s):  
Hawraa Hadi Abass ◽  
Bushra A Hasan
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Blue Shift ◽  
Oxide Content ◽  
Structural And Optical Properties ◽  
Consistent Manner ◽  
Nanocrystalline Thin Films ◽  
Doping Ratio

AlO-doped ZnO nanocrystalline thin films from with nano crystallite size in the range (19-15 nm) were fabricated by pulsed laser deposition technique. The reduction of crystallite size by increasing of doping ratio shift the bandgap to IR region the optical band gap decreases in a consistent manner, from 3.21to 2.1 eV by increasing AlO doping ratio from 0 to 7wt% but then returns to grow up to 3.21 eV by a further increase the doping ratio. The bandgap increment obtained for 9% AlO dopant concentration can be clarified in terms of the Burstein–Moss effect whereas the aluminum donor atom increased the carrier's concentration which in turn shifts the Fermi level and widened the bandgap (blue-shift). The engineering of the bandgap by low concentration of AlO dopant makes ZnO: AlO thin films favorable for the fabrication of optoelectronic devices. The optical constants were calculated and was found to be greatly affected by the increasing the doping ratio.

STRUCTURAL PARAMETERS AND OPTICAL CONSTANTS OF CdS NANOCRYSTALLINE THIN FILMS

NANO ◽  
2011 ◽  
Vol 06 (03) ◽  
pp. 251-258 ◽  
Author(s):  
B. VISWANATHAN ◽  
J. DHARMARAJA ◽  
J. BALAMURUGAN
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Band Gap ◽  
Crystallite Size ◽  
Optical Conductivity ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Structural Parameters ◽  
Stoichiometric Composition ◽  
Bath Temperature

Optical constants of cadmium sulfide (CdS) thin films were determined in the spectral range of 400–1200 nm from optical absorption and transmittance measurements for different bath temperatures. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) were the techniques used to determine the crystallite structure and morphology of the films. EDX images showed that a sample had a stoichiometric composition. The crystallite size and microstrain were calculated using the Williamson–Hall method. The optical band gap values of the films varied from 2.35 eV to 2.5 eV, depending on the bath temperature. Optical study was performed to calculate the refractive index (n), extinction coefficient (k), optical conductivity (σ), dielectric constant (real and imaginary), and optical band gap using transmission spectra. It has been observed that the conductivity of the synthesized films has a close relationship with the size of the crystallites. The optical conductivity and the crystallite size increase at a temperature of up to 70°C and then start decreasing when the temperature is still increased due to the change in phase from hexagonal to cubic in nature. Moreover, we observed that beyond this temperature the XRD peak shifts toward the nanoregion. The values of microstructure parameters change drastically, whereas the trend of optical constants remains the same.

scholarly journals Effects of multi- Deposition on the structural and optical properties of CdS nanocrystalline thin film prepared by CBD technique.

2019 ◽  
Vol 11 (20) ◽  
pp. 68-74
Author(s):  
Jamal. F. Mohammad
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Ph Value ◽  
Blue Shift ◽  
Ammonia Solution ◽  
Structural And Optical Properties ◽  
Nanocrystalline Thin Film ◽  
Vis Spectroscopy ◽  
Nanocrystalline Thin Films

Cadmium sulfide (CdS) nanocrystalline thin films have been prepared by chemical bath deposition (CBD) technique on commercial glass substrates at 70ºC temperature. Cadmium chloride (CdCl2) as a source of cadmium (Cd), thiourea (CS(NH2)2) as a source of sulfur and ammonia solution (NH4OH) were added to maintain the pH value of the solution at 10. The characterization of thin films was carried out through the structural and optical properties by X-ray diffraction (XRD) and UV-VIS spectroscopy. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin film and it showed a blue shift with respect to the bulk value (from 3.9 - 2.4eV). In present work effects of thickness on the structural and optical properties of CdS nanocrystalline thin films were discussed.

Investigation of Annealing on the Structural and Optical Properties of Chemical Bath Deposited ZnSe Quantum Dot Thin Films

2012 ◽  
Vol 229-231 ◽  
pp. 10-13
Author(s):  
Liang Yan Chen ◽  
Chao Fang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Quantum Effect ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Znse Quantum Dot ◽  
Znse Thin Films

ZnSe thin films were obtained through chemical bath deposition method. Structural and optical properties of as deposited and annealed samples were investigated by X-ray Diffraction and spectrophotometer. The as deposited thin films were in nanocrystalline, with lots of strain and a blue shift of optical band gap. After annealing, the crystal grain gained, the strain eased and optical band gap enlarged. And it suggested that annealing can ease the quantum effect of chemical bath deposited ZnSe thin films.

Blue shift in the optical band gap of amorphous Hf–In–Zn–O thin films deposited by RF sputtering

2012 ◽  
Vol 525 ◽  
pp. 172-174 ◽  
Author(s):  
Anup Thakur ◽  
Se-Jun Kang ◽  
Jae Yoon Baik ◽  
Hanbyeol Yoo ◽  
Ik-Jae Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Rf Sputtering ◽  
Blue Shift

Structural and optical properties of GaN-based nanocrystalline thin films

2008 ◽  
Vol 516 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
C.E.A. Grigorescu ◽  
L. Tortet ◽  
O. Monnereau ◽  
L. Argeme ◽  
H.J. Trodahl ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Structural And Optical Properties ◽  
Nanocrystalline Thin Films

Effect of Tin Composition on Cu2ZnSnS4 Photovoltaic Absorbers

2012 ◽  
Vol 534 ◽  
pp. 156-159 ◽  
Author(s):  
Dong Hua Fan ◽  
Rong Zhang ◽  
Hui Ren Peng
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Band Gap ◽  
Crystallite Size ◽  
Optical Band Gap ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poor Condition ◽  
Czts Thin Films

Cu2ZnSnS4 (CZTS) thin films are prepared by sulfurizing the precursors deposited by vacuum evaporation methods. The samples sulfurized at 500°C for 3h shows the strong (112) diffraction peak at 28.45˚, suggesting the successful synthesis of CZTS thin films. The X-ray diffraction shows that CZTS thin film prepared in Sn-poor condition have the best crystallinity. The Sn-dependent crystallite size was calculated to be 19.53-21.03 nm. In addition, we found that the optical band gap with various Sn contents can be modulated at 1.48-1.85 eV

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