The calculate of optical gap energy and urbach energy of Ni1−xCoxO thin films

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.

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Epoxy/Silicone Blend Loaded with N-Doped CNT Composites: Study on the Optoelectronic Properties

International Journal of Photoenergy ◽

10.1155/2021/3749722 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Younes Ziat ◽

Hamza Belkhanchi ◽

Maryama Hammi ◽

Ousama Ifguis

Keyword(s):

Thin Films ◽

Urbach Energy ◽

Optical Transition ◽

Sol Gel ◽

Visible Range ◽

Visible Spectroscopy ◽

Glass Substrates ◽

Optical Gap ◽

Ito Glass ◽

Uv Visible

Thin films of epoxy/silicone loaded with N-CNT were prepared by a method of sol-gel and deposited on ITO glass substrates at room temperature. The properties of the loaded monolayer samples (0.00, 0.07, 0.1, and 0.2 wt% N-CNTs) were analyzed by UV-visible spectroscopy. The transmittance for the unloaded thin films is 88%, and an average transmittance for the loaded thin film is about 42 to 67% in the visible range. The optical properties were studied from UV-visible spectroscopy to examine the transmission spectrum, optical gap, Tauc verified optical gap, and Urbach energy, based on the envelope method proposed by Swanepoel (1983). The results indicate that the adjusted optical gap of the film has a direct optical transition with an optical gap of 3.61 eV for unloaded thin films and 3.55 to 3.19 eV for loaded thin films depending on the loading rate. The optical gap is appropriately adapted to the direct transition model proposed by Tauc et al. (1966); its value was 3.6 eV for unloaded thin films and from 3.38 to 3.1 eV for loaded thin films; then, we determined the Urbach energy which is inversely variable with the optical gap, where Urbach’s energy is 0.19 eV for the unloaded thin films and varies from 0.43 to 1.33 eV for the loaded thin films with increasing rate of N-CNTs. Finally, nanocomposite epoxy/silicone N-CNT films can be developed as electrically conductive materials with specific optical characteristics, giving the possibility to be used in electrooptical applications.

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Preparation and Properties of Hydrogen Ated Amorphous Germanium Nitride a-GeNx:H

MRS Proceedings ◽

10.1557/proc-467-543 ◽

1997 ◽

Vol 467 ◽

Cited By ~ 1

Author(s):

M. Hioki ◽

S. Nitta ◽

Y. Takeda ◽

K. Yamamoto ◽

M. Sasaki ◽

...

Keyword(s):

Magnetic Field ◽

Outer Edge ◽

Optical Absorption Coefficient ◽

Gap Energy ◽

Optical Gap ◽

Light Yellow ◽

Carbon Impurities ◽

Optical Gap Energy ◽

The Magnetic Field ◽

Content Of Oxygen

ABSTRACTThe properties of a-GeNx:H films have been studied including the effects of oxygen and carbon impurities. The contamination of a-GeNx:H with oxygen and carbon is expressed as a-GeNx(OyCz):H, where x=N/Ge, y=O/Ge and z=C/Ge. The characteristics of a-GeNx(OyCz):H are summarized as follows: the sample is transparent at the center of a film, and the color of a film varies to light yellow and to brown at the outer edge depending on the magnetic field of the magnetron sputtering. The compositional ratios of the film vary from x=0.34 to 0.28, y=0.15 to 0.25 and z=0.05 to 0.02 at the center and at outer edge of a film, respectively. Optical gap energy EO5, obtained by the photon energy at optical absorption coefficient of 5×103 cm−1, are 2.9 eV at the center and 1.7 eV at the outer edge of a film. Eo5 increases with the nitrogen content x in a-GeNx(OyCz):H but is independent of the content of oxygen and carbon.

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