scholarly journals Effects of the Argon Pressure on the Optical Band Gap of Zinc Oxide Thin Films Grown by Nonreactive RF Sputtering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
M. Acosta ◽  
I. Riech ◽  
E. Martín-Tovar

Zinc oxide (ZnO) thin films were grown by nonreactive RF sputtering at room temperature under varying argon pressures (PAr). Their optical band gap was found to increase from 3.58 to 4.34 eV when the argon pressure increases from 2.67 to 10.66 Pa. After annealing at 200°C and 500°C, optical band gaps decrease considerably. The observed widening of the band gap with increasingPArcan be understood as being a consequence of the poorer crystallinity of films grown at higher pressures. Measurements of morphological and electrical properties of these films correlate well with this picture. Our main aim is to understand the effects ofPAron several physical properties of the films, and most importantly on its optical band gap.

2011 ◽  
Vol 197-198 ◽  
pp. 1766-1770 ◽  
Author(s):  
Dong Ping Zhang ◽  
Ping Fan ◽  
Zhuang Hao Zheng ◽  
Li Li Ru ◽  
Jian Jun Huang ◽  
...  

ZnO thin films were prepared by DC reactive magnetron sputtering at room temperature. Two of them were annealed with different modes under vacuum condition. One was annealed with constant temperature of 300°C ; the other was annealed with temperature rising step by step from room temperature to 300°C . By comparing the microstructure and optical properties of the as-grown and annealed samples, the effects of different annealing modes on ZnO films performances were revealed. The experiment results investigated that the sample annealed with constant temperature of 300°C has the high grain size and surface roughness. Both of the two annealing modes could release the intrinsic stresses to some degree. The optical band gap of the samples narrowed after annealing, and the two annealed samples have almost the same band gap. Strong green emissions are observed for all the samples, but the emission intensity decreased of the sample annealed with the temperature rising step by step compared with that of other samples.


RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6278-6287 ◽  
Author(s):  
Rajesh V. Hariwal ◽  
Hitendra K. Malik ◽  
Ambika Negi ◽  
Asokan Kandasami

The defects in the host lattice play a major role in tuning the surface roughness, optical band gap and the room temperature ferromagnetism of ZnO thin films.


2012 ◽  
Vol 525 ◽  
pp. 172-174 ◽  
Author(s):  
Anup Thakur ◽  
Se-Jun Kang ◽  
Jae Yoon Baik ◽  
Hanbyeol Yoo ◽  
Ik-Jae Lee ◽  
...  

Optik ◽  
2018 ◽  
Vol 164 ◽  
pp. 143-154 ◽  
Author(s):  
Asim Jilani ◽  
M.Sh. Abdel-wahab ◽  
H.Y. Zahran ◽  
I.S. Yahia ◽  
Attieh A. Al-Ghamdi ◽  
...  

2018 ◽  
Vol 5 (3) ◽  
pp. 9089-9093 ◽  
Author(s):  
Nishant Kumar ◽  
Anu Katiyar ◽  
Anchal Srivastava

2019 ◽  
Vol 27 (04) ◽  
pp. 1950138
Author(s):  
FATMA MEYDANERİ TEZEL ◽  
İ. AFŞIN KARİPER

Undoped and silver, lithium and cobalt-doped ZnO thin films have been successfully deposited on glass by chemical bath deposition (CBD). The reaction temperature was 50∘C and the films were annealed at 400∘C for 4[Formula: see text]h in a high temperature furnace. UV/VIS spectrum was used to determine optical transmittance, optical band gap ([Formula: see text] and absorbance values of Ag:ZnO, Co:ZnO, Li:ZnO and undoped ZnO thin films. Optical band gap ([Formula: see text] and absorbance values of undoped ZnO, Ag:ZnO, Co:ZnO and Li:ZnO thin films were found as 0.0158, 0.0064, 0.2638, 0.0956 and 3.24, 3.13, 3.27, 2.96 eV, respectively. Extinction coefficients and refraction indexes of the films were found to be 0.0096, 0.0038, 0.0068, 0.019 (extinction coefficient) and 1.26, 1.14, 1.66, 2.33 (refraction index), respectively. X-ray patterns of undoped ZnO, Ag:ZnO, Co:ZnO and Li:ZnO thin films were confirmed as amorphous.


2019 ◽  
Vol 26 (03) ◽  
pp. 1850158 ◽  
Author(s):  
MARYAM MOTALLEBI AGHGONBAD ◽  
HASSAN SEDGHI

Zinc Oxide thin films were deposited on glass substrates by sol–gel spin coating method. Zinc acetate dihydrate, 2-methoxyethanol and monoethanolamine were used as precursor, solvent and stabilizer, respectively. Zinc acetate dihydrate was used with different molar concentrations of 0.15, 0.25 and 0.5 M. Optical properties of ZnO thin films such as dielectric constants, absorption coefficient, Urbach energy and optical band gap energy were calculated by spectroscopic ellipsometry (SE) method. The effect of zinc acetate concentration on optical properties of ZnO thin films is investigated. ZnO thin film with Zn concentration of 0.25 M had the highest optical band gap. Wemple DiDomenico oscillator model was used for calculation of the energy of effective dispersion oscillator, the dispersion energy, the high frequency dielectric constant, the long wavelength refractive index and the free carrier concentration.


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