scholarly journals Fabrication and Optoelectronic Properties of Fluoride Tin Oxides/Porous Silicon/p-Silicon Heterojunction

2014 ◽  
Vol 36 ◽  
pp. 142-152 ◽  
Author(s):  
Hasan A. Hadi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Porous Silicon ◽  
Band Gap ◽  
Tin Oxide ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Tin Oxides ◽  
Uv Visible ◽  
P Type

In this paper, formation of a nanostructure semi transparence fluoride tin oxides (FTO) by spray pyrolysis technique on porous silicon PS layer. Porous silicon PS layer was prepared by anodization of p-type silicon wafers to fabricate of the UV- Visible Fluoride-doped tin oxide /Porous silicon /p-Si heterojunction photodetector. Optical properties of FTO thin films were measured. The optical band gap of 3.77 eV for SnO2:film was deduced. From (I-V) and (C-V) measurements, the barrier height for FTO/PS diode was of 0.77 eV, and the built in voltage , which was of 0.95 V. External quantum efficiency was 55 % at 500 nm which corresponding to peak responsivity of 1.15 A/W at 1 V bias. The PS band gap in the vicinity of PS/c-Si heterojunction was 1.38 eV.

scholarly journals Optical properties of CdO thin films

2010 ◽  
Vol 7 (1) ◽  
pp. 10-13
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Glass Substrate ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Cadmium Oxide ◽  
Localized States ◽  
Different Temperatures ◽  
Cdo Thin Films

Cadmium Oxide thin films were deposited on glass substrate by spray pyrolysis technique at different temperatures (300,350,400, 500)oC. The optical properties of the films were studied in this work. The optical band-gap was determined from absorption spectra, it was found that the optical band-gap was within the range of (2.5-2.56)eV also width of localized states and another optical properties.

scholarly journals Influence of Ag-Dopant on Structural Optical and Electrical Properties of Cu(1-x)AgxO Thin Films Prepared By Chemical Spray Pyrolysis Technique

2018 ◽  
Vol 4 (5) ◽  
pp. 542-545 ◽  
Author(s):  
R. Shabu ◽  
A. Moses Ezhil Raj
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Spray Pyrolysis ◽  
Optical Band Gap ◽  
Spray Pyrolysis Technique ◽  
Precursor Solution ◽  
Oxide Semiconductor ◽  
Chemical Spray Pyrolysis ◽  
Chemical Spray Pyrolysis Technique ◽  
Chemical Spray

As major attention has been paid to transition metal oxide semiconductor suitable for solar cell, photo detector and gas sensor, present study embark on the structural, optical and electrical characterization of Ag doped CuO thin films prepared using chemical spray pyrolysis technique at the constant substrate temperature of 350 �C. For Ag doping, various concentrations of silver acetate (0.5-3.0 wt.%) was used in the sprayed precursor solution. Confirmed monoclinic lattice shows the tenorite phase formation of CuO in the pure and Ag doped films. The optical band gap of the films was in the range of 2.4 -3.4 eV. A minimum resistivity of 0.0017x103 ohmcm was achieved in the 0.5 wt.% Ag doped film, and its optical band gap was 2.74 eV.

Effects of Nitrogen Doping on Optical Properties of Tungsten Oxide Thin Films

2012 ◽  
Vol 616-618 ◽  
pp. 1773-1777
Author(s):  
Xi Lian Sun ◽  
Hong Tao Cao
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Tungsten Oxide ◽  
Nitrogen Doping ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Tungsten Oxide Thin Films

In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

Absorber Films of Antimony Chalcogenides via Chemical Deposition for Photovoltaic Application

2004 ◽  
Vol 836 ◽  
Author(s):  
M. T. S. Nair ◽  
Y. Rodríguez-Lazcano ◽  
Y. Peña ◽  
S. Messina ◽  
J. Campos ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Chemical Deposition ◽  
Dark Conductivity ◽  
Glass Substrates ◽  
Photovoltaic Application ◽  
Sodium Selenosulfate ◽  
P Type ◽  
Antimony Chalcogenides

ABSTRACTAntimony sulfide thin films (300 nm) have been deposited on glass substrates at 1–10°C from chemical bath. When heated these become crystalline and photoconductive with optical band gap (direct) of 1.7 eV. Thin films formed from chemical baths containing SbCl3 and sodium selenosulfate are of mixed phase Sb2O3/Sb2Se3, which when heated in the presence of Se-vapor converts to single phase Sb2Se3 film with optical band gap of 1.1 eV. Such films possess dark conductivity of 10-8 ohm-1cm-1 and show photosensitivity of two orders. Reaction of Sb2S3-CuS in nitrogen at 400°C produces crystalline, photoconductive p-type CuSbS2 with optical band gap (direct) of 1.5 eV. By controlling the deposition and heating condition, (i)Sb2S3-(p)CuSbS2 layer is formed, which is utilized in a photovoltaic structure, (n)CdS:In-(i)Sb2S3-(p)CuSbS2, with a Voc of 345 mV and Jsc 0.18 mA/cm2 under 1 kW m-2 tungsten halogen illumination. In the case of a structure, CdS:Cl-Sb2S3-Cu2-xSe, Voc of 350 mV and Jsc of 0.5 mA/cm2 are observed.

scholarly journals Effect of gamma irradiation on structural, morphological and optical properties of p-quaterphenyl thin films

2018 ◽  
Vol 14 (2) ◽  
pp. 5624-5637
Author(s):  
A.A. Attia ◽  
M.M. Saadeldin ◽  
K. Sawaby
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Surface Morphology ◽  
Absorption Coefficient ◽  
Gamma Irradiation ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation Method ◽  
Single Oscillator Model

Para-quaterphenyl thin films were deposited onto glass and quartz substrates by thermal evaporation method. p-quaterphenyl thin films wereexposed to gamma radiation of Cobat-60 radioactive source at room temperature with a dose of 50 kGy to study the effect of ?-irradiation onthe structure and the surface morphology as well as the optical properties of the prepared films. The crystalline structure and the surface morphology of the as-deposited and ?-irradiated films were examined using the X-ray diffraction and the field emission scanning electron microscope. The optical constants (n & k) of the as-deposited and ?-irradiated films were obtained using the transmittance and reflectance measurements, in the wavelength range starting from 250 up to 2500 nm. The analysis of the absorption coefficient data revealed an allowed direct transition with optical band gap of 2.2 eV for the as-deposited films, which decreased to 2.06 eV after exposing film to gamma irradiation. It was observed that the Urbach energy values change inversely with the values of the optical band gap. The dispersion of the refractive index was interpreted using the single oscillator model. The nonlinear absorption coefficient spectra for the as-deposited and ?-irradiated p-quaterphenyl thin films were obtained using the linear refractive index.

scholarly journals Effects of Sintering Atmosphere on the Optical, Thermal and Electrical Properties of Inkjet Printed ZnxCu(1-x)Fe2O4 Thin Films

2021 ◽  
Vol 81 (2) ◽  
pp. 25-35
Author(s):  
Lim Joon Hoong
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Band Gap ◽  
Optical Band Gap ◽  
Electronic Band Structure ◽  
Copper Ferrite ◽  
Electronic Band ◽  
Sintering Atmosphere ◽  
P Type

The effects of sintering atmosphere on the optical, thermal and electric properties of inkjet printed ZnxCu(1-x)Fe2O4 thin films have been investigated. The thin film samples were sintered separately in vacuum and oxygen. The obtained samples were then characterized by X-ray diffraction (XRD), optical band gap, electrical conductivity, Seebeck coefficient and thermal conductivity. XRD analysis showed that the fabricated samples have a cubic spinel structure of zinc copper ferrite regardless of the sintering atmosphere. The electrical conductivity of ZnxCu(1-x)Fe2O4 thin films sintered in oxygen was about 5 % higher compared to ZnxCu(1-x)Fe2O4 thin films sintered in vacuum. The optical band gap shows that the samples sintered in oxygen had smaller band gap compared to samples sintered in vacuum. The electronic band structure simulated through ABINIT shows ZnxCu(1-x)Fe2O4 is an indirect band gap material. A smaller electronic band gap was observed in O2 rich condition and was in agreement with the optical band gap and electrical conductivity test results. Seebeck coefficient of ZnxCu(1-x)Fe2O4 thin films sintered in oxygen remained positive , confirming charge transport by hole carries as p-type semiconductors. A change from p-type to n-type semiconductors was observed when ZnxCu(1-x)Fe2O4 thin films sintered in vacuum.

scholarly journals Conductivity and Density of States of New Polyphenylquinoline

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 934 ◽  
Author(s):  
Shamil R. Saitov ◽  
Dmitriy V. Amasev ◽  
Alexey R. Tameev ◽  
Vladimir V. Malov ◽  
Marine G. Tedoradze ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Band Gap ◽  
Density Of States ◽  
Optical Band Gap ◽  
Dark Conductivity ◽  
Localized States ◽  
Energy Distance ◽  
Temperature Dependences

Electrical, photoelectrical, and optical properties of thin films of a new heat-resistant polyphenylquinoline synthesized using facile methods were investigated. An analysis of the obtained temperature dependences of the dark conductivity and photoconductivity indicates the hopping mechanism of conductivity over localized states arranging at the energy distance of 0.8 eV from the Fermi level located inside the band gap of the investigated material. The optical band gap of the studied material was estimated from an analysis of the spectral dependences of the photoconductivity and absorption coefficient before (1.8–1.9 eV) and after (2.0–2.2 eV) annealing at temperatures exceeding 100 °C. The Gaussian character of the distribution of the localized states of density inside the band gap near the edges of the bands was established. A mechanism of changes in the optical band gap of the investigating polymer under its annealing is proposed.

Properties of TiO2 Thin Film Prepared by Sol-Gel Dip Coating

2015 ◽  
Vol 723 ◽  
pp. 528-531
Author(s):  
Jun Wang ◽  
Ling Yun Bai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Dip Coating ◽  
Gel Method ◽  
Glass Substrates

TiO2 thin films were prepared on glass substrates by sol-gel method. The effect of withdraw speed on the thickness and optical properties of TiO2 thin films was investigated. The films were transparent in the visible wavelength. The thickness of the TiO2 films was increased from 90 nm for the withdraw speed of 1000 μm/s to 160 nm for the withdraw speed of 2000 μm/s. While, The refractive index of the TiO2 thin film decreased from 2.38 to 2.07. It may be due to the porosity of the film was increased. The optical band-gap of the films was around 3.45 eV.

Single Phase CuO Thin Films Prepared by Thermal Oxidation in Air with Water Vapor

2015 ◽  
Vol 1109 ◽  
pp. 544-548 ◽  
Author(s):  
Jian Bo Liang ◽  
Xu Yang Li ◽  
Naoki Kishi ◽  
Tetsuo Soga
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Optical Properties ◽  
Water Vapor ◽  
Band Gap ◽  
Thermal Oxidation ◽  
Single Phase ◽  
Optical Band Gap ◽  
Structural And Optical Properties ◽  
Oxidation In Air

Single phase CuO films have been successfully synthesized by thermal oxidation of cupper foil in air with water vapor. The structural and optical properties of CuO films were investigated. It is observed that the grain size increases with increasing the oxidation temperature. The optical band gap of CuO film is determined by the transmittance and reflectance spectra.

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