scholarly journals The calculation of the optical gap energy of ZnXO (X = Bi, Sn and Fe)

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 714-720 ◽  
Author(s):  
Said Benramache ◽  
Boubaker Benhaoua

AbstractIn this paper, a new mathematical model has been developed to calculate the optical properties of nano materials a function of their size and structure. ZnO has good characterizatics in optical, electrical, and structural crystallisation; We will demonstrate that the direct optical gap energy of ZnO films grown by US and SP spray deposition can be calculated by investigating the correlation between solution molarity, doping levels of doped films and their Urbache energy. A simulation model has been developed to calculate the optical band gap energy of undoped and Bi, Sn and Fe doped ZnO thin films. The measurements by thus proposed models are in agreement with experimental data, with high correlation coefficients in the range 0.94-0.99. The maximum calculated enhancement of the optical gap energy of Sn doped ZnO thin films is always higher than the enhancement attainable with an Fe doped film, where the minimum error was found for Bi and Sn doped ZnO thin films to be 2,345 and 3,072%, respectively. The decrease in the relative errors from undoped to doped films can be explained by the good optical properties which can be observed in the fewer number of defects as well as less disorder.

2016 ◽  
Vol 8 (1) ◽  
pp. 01008-1-01008-5
Author(s):  
Said Benramache ◽  
◽  
Boubaker Benhaoua ◽  
Okba Belahssen ◽  
◽  
...  

2020 ◽  
Vol 10 (5) ◽  
pp. 642-648
Author(s):  
Ehsan M. Aghkonbad ◽  
Hassan Sedghi ◽  
Maryam M. Aghgonbad

Background: Al-doped ZnO thin films are considered as a promising alternative to ITO in optoelectronic applications. In this work, Al-doped ZnO thin films were prepared using sol-gel spin coating technique. Experimental: The optical properties of the films such as refractive index, extinction coefficient, dielectric function and the absorption coefficient were examined using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. The effect of Al doping on ZnO thin films with different Al concentrations was significant. Tauc relation was used to estimate the optical band gap energy of the films. Results: The calculated values of band gap energy were obtained between 3.10 to 3.25 eV. Also the fraction of voids was calculated using Aspnes theory. Conclusion: The free carrier concentration value was obtained in the order of 1019 cm-3.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 252 ◽  
Author(s):  
A. M. Alsaad ◽  
A. A. Ahmad ◽  
I. A. Qattan ◽  
Qais M. Al-Bataineh ◽  
Zaid Albataineh

Undoped ZnO and group III (B, Al, Ga, and In)-doped ZnO thin films at 3% doping concentration level are dip-coated on glass substrates using a sol-gel technique. The optical properties of the as-prepared thin films are investigated using UV–Vis spectrophotometer measurements. Transmittance of all investigated thin films is found to attain high values of ≥80% in the visible region. We found that the index of refraction of undoped ZnO films exhibits values ranging between 1.6 and 2.2 and approximately match that of bulk ZnO. Furthermore, we measure and interpret nonlinear optical parameters and the electrical and optical conductivities of the investigated thin films to obtain a deeper insight from fundamental and practical points of view. In addition, the structural properties of all studied thin film samples are investigated using the XRD technique. In particular, undoped ZnO thin film is found to exhibit a hexagonal structure. Due to the large difference in size of boron and indium compared with that of zinc, doping ZnO thin films with these two elements is expected to cause a phase transition. However, Al-doped ZnO and Ga-doped ZnO thin films preserve the hexagonal phase. Moreover, as boron and indium are introduced in ZnO thin films, the grain size increases. On the other hand, grain size is found to decrease upon doping ZnO with aluminum and gallium. The drastic enhancement of optical properties of annealed dip-synthesized undoped ZnO thin films upon doping with group III metals paves the way to tune these properties in a skillful manner, in order to be used as key candidate materials in the fabrication of modern optoelectronic devices.


2014 ◽  
Vol 38 (1) ◽  
pp. 93-96
Author(s):  
E Hoq ◽  
MRA Bhuiyan ◽  
J Begum

Sb doped ZnO thin films having various thicknesses have been prepared onto glass substrate by using thermal evaporation method. The atomic compositions of the grown films have been determined by Energy Dispersive Analysis of X-ray (EDAX) method. The optical properties were measured by using a UV-VIS-NIR spectrophotometer (300 to 2500 nm). The EDAX analysis revealed that Sb is doped into the ZnO films. Optical properties showed high absorption coefficient (~105/cm) that direct allowed transition band gap. The optical band gap of the ZnO thin films became reduced due to the doping of Sb. DOI: http://dx.doi.org/10.3329/jbas.v38i1.20217 Journal of Bangladesh Academy of Sciences, Vol. 38, No. 1, 93-96, 2014


Author(s):  
Ali sadek Kadari ◽  
Abdelkader Nebatti Ech-Chergui ◽  
Mohamed walid Mohamedi ◽  
Abdelhalim Zoukel ◽  
Tair Sabrina ◽  
...  

Abstract Pure and Al-doped ZnO thin films were successfully deposited with sol-gel dip coating on both substrates Si (100) and glass. The structural, chemical, morphological and optical properties as a function of the annealing temperature and dopant atomic concentration were investigated by means of X-ray diffraction, Energy dispersive X-ray, Scanning Electron Microscopy, and spectrophotometry. All the pure and doped films show a polycrystalline nature and hexagonal in structure. Accurate doping was proven by EDX. In addition, the SEM analysis revealed that the films possess uniform distribution throughout the surface and the grain dimension decreases with Al doping. From the transmittance measurements, it is see that all films are over 55% in the visible region and the band gap energy increases from 3.28 to 3.45 eV with the increase of Al concentration.


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