Effect of annealing temperature on optical properties and photocatalytic properties of TiO2:N 8% thin film for rhodamine B degradation

2018 ◽  
Vol 5 (8) ◽  
pp. 086404
Author(s):  
Ike Fetty Dayanti Pandiangan ◽  
Heri Sutanto ◽  
Iis Nurhasanah
2018 ◽  
Vol 1011 ◽  
pp. 012016 ◽  
Author(s):  
Nandani ◽  
A Supriyanto ◽  
A H Ramelan ◽  
F Nurosyid

2014 ◽  
Vol 979 ◽  
pp. 248-250 ◽  
Author(s):  
Thanat Srichaiyaperk ◽  
Kamon Aiempanakit ◽  
Mati Horprathum ◽  
Pitak Eiamchai ◽  
Chanunthorn Chananonnawathorn ◽  
...  

Tungsten trioxide (WO3) thin films were prepared by a DC reactive magnetron sputtering technique. The thin film fabrication process used tungsten (99.995%) as the sputtering target, the mixture of argon and oxygen as sputtering and reactive gases, and silicon (100) and glass slides as the substrates. The effects of annealing temperature in the range of 200-400°C on physical and optical properties of the WO3 thin films were investigated. The nanostructures and morphologies of these films were characterized by grazing-incident X-ray diffraction (GIXRD) and field-emission scanning electron microscopy (FE-SEM). The optical properties were analyzed by variable-angle spectroscopic ellipsometry (VASE) and spectrophotometer. From the XRD results, the as-deposited and annealed WO3 thin films up to 300°C were all amorphous. Only the WO3 thin film annealed at 400°C exhibited a polycrystalline monoclinic phase. The FE-SEM cross-sections and surface topologies demonstrated nearly identical thin-film thickness and physical grain sizes. The SE analyses showed that the thin films were all homogeneous dense layers with additional surface roughness. With the annealing treatment, the thin film thickness was slightly decreased. The SE physical model was best optimized with the Cauchy optical model. The results showed that the refractive index at 550 nm was increased from 2.17 to 2.23 with the increased annealing temperature. The results from the spectrophotometer confirmed that the optical spectra for the WO3 thin films were decreased. This study demonstrated that, the thin film annealed at 400°C exhibited the slightly lower transparency, which corresponded to the results from the GIXRD and SE analyses.


Author(s):  
Abubakr Mahmoud Hamid ◽  
Hassan Wardi Hassan ◽  
Fatima Ahmed Osman

Solar energy is already has being widely successfully used in residential and industrial setting for thermal and electrical application such as space technology, communication, etc. I. Aims: The aim of this study the effect of the annealing temperature in improvement optical properties of titanium oxide nanostructure doped iron oxide for use in thin film. Study Design: The spray pyrolysis deposition method used for preparation the nanostructure material. Place and Duration of Study: This study was conducted in department of physics and department of materials sciences, Al-Neelain University, between January 2016 and January 2019.  Methodology: Thin films of Titanium Oxide (TiO2) doped Iron Oxide (Fe2O3) have been prepared by chemical spray pyrolysis deposition technique. A laboratory designed glass atomizer was used for spraying the aqueous solution. Which has an output nozzle about 1 mm. then film were deposited on preheated cleaned glass substrates at temperature of 400°C. we used different concentration to study optical parameters. A 1.5 g TiO2 powder of anatase structure doped with 1.5 g of Fe2O3 was mixed with 2 ml of ethanol and stirred using a magnetic stirrer for 30 minutes to form TiO2 paste to obtain the starting solution for deposition and spray time was 10 s and spray interval 2 min was kept constant. The carrier gas (filtered compressed air) was maintained at a pressure of 105 Nm-2, and distance between nozzle and substrate was about 30 cm ± 1 cm. Thickness of sample was measured using the weighting method and was found to be around 400nm. Optical transmittance and absorbance were record in wavelength range of (200-1100) nm using UV-Visible spectrophotometer (Shimadzu Company Japan). Results: The results obtained showed that the optical band gap decreased from 5.6eV before annealing to (3.9, 3.26, 3.24 and 3.27 eV) after annealing temperature at(450° – 500°) for TiO2:Fe2O3 thin films, this result refer to the broadening of  secondary levels that product by TiO2: doping to the Fe2O2thin films. Also the results showed the variation of refractive index with wavelength for different concentration after annealing temperature at (450° – 500°) of TiO2: Fe2O3 films from this figure, it is clear that n decrease with low concentration and increase with high concentration after annealing temperature that mean the density is decreased of this films. In addition the extinction coefficient of TiO2:Fe2O3 thin films recorded before annealing and with different concentration (1.1, 1.2, 1,5 and 1,6) and in the range of (300 – 1200) nm and at annealing temperature from (450° – 500°). It observed from that the extinction coefficient, decrease sharply with the increase of wavelength for all prepared films and all the sample after annealing is interference between them accept the sample before annealing is far from the other sample. Conclusion: The TiO2 thin film shows better result after annealing; By exposing temperature during annealing process degree at (450o- 500o) is found to be the best temperature for annealing TiO2 thin film. The study concluded that an annealing temperature Contributes to the improvement of optical properties related to increasing the efficiency of the solar cell, especially the refractive index, energy gap, extinction coefficient.


Author(s):  
Sabah M. Ahmed ◽  
Raghad Y. Mohammed ◽  
Sedki O. Yousif

Introduction: CdSe is an important II–VI semiconducting material due to its typical optical properties such as small direct band gap (1.7 eV) and a high refractive index and, thus, a major concern is focused on the investigation of optical properties of CdSe thin films which is important to promote the performances of the devices of solid -state such as SC (solar cells), thin film transistors, LED (light-emitting diodes), EBPL (electron–beam pumped lasers) and electroluminescent devices. In the present work, CdSe thin films were deposited by thermal evaporation method and the results have been analysed and presented. Materials and Methods: CdSe thin films has been deposited on glass microscopic slides as substrates of (75×25×1 mm) under room temperature using PVD technique. CdSe blended powders gets evaporated and condensed on the substrate. The film thickness (t = 100 ± 5 nm) which is measured using Michelson interferometry method. Transmission spectrum, from 200-1100 nm, are scanned using two beams UV–VIS Spectrophotometer (6850 UV/Vis. Spectrophotometer-JENWAY). The deposited films then were annealed at temperature range of (1500C to 3500C) under vacuum to have a stable phase of the material and prevent surface oxidization. Results and Discussion: A transmittance spectrum of CdSe thin film is scanned over wavelength range 200 to 1100 nm using a (6850 UV/Vis. Spectrophotometer-JENWAY) at room temperature. The transmittance percentage between the as-deposited film and the annealed films change varies from (17.0%) to (47.0%). It is clearly seen that there is a shift toward higher energy (Blue Shift) in the transmittance spectrum. As annealing temperature increased the transmittance edge is shifted to the longer wavelength (i.e., after annealing the CdSe films shows red shifts in their optical spectra). The band gap was found within the range 1.966-1.7536 eV for CdSe thin film. As annealing temperature increases, the Eg continuously decreases. Conclusions: CdSe thin films have been deposited using Physical Vapor Deposition (PVD) Technique. It is found that the transmission for as- deposited films is (17%) and increases to (47%) as annealing temperature increases. Beside this the energy gap for as- deposited CdSe film is (1.966eV) and decreased from (1.909 eV) to (1.7536eV) as the annealing temperature increases. There is a strong red shift in the optical spectrum of the annealed CdSe films. There is a gradual shift of the annealed films thin film spectra as compared of bulk CdSe films.


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