scholarly journals Deposition of Nanostructured CdS Thin Films by Thermal Evaporation Method: Effect of Substrate Temperature

Materials ◽  
2017 ◽  
Vol 10 (7) ◽  
pp. 773 ◽  
Author(s):  
Nafiseh Memarian ◽  
Seyeed Rozati ◽  
Isabella Concina ◽  
Alberto Vomiero
2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Cheng-Fu Yang ◽  
Wei Chen

The antimony-telluride (Sb2Te3) thermoelectric thin films were prepared on SiO2/Si substrates by thermal evaporation method. The substrate temperature that ranged from room temperature to 150°C was adopted to deposit the Sb2Te3thin films. The effects of substrate temperature on the microstructures and thermoelectric properties of the Sb2Te3thin films were investigated. The crystal structure and surface morphology of the Sb2Te3thin films were characterized by X-ray diffraction analyses and field emission scanning electron microscope observation. The RT-deposited Sb2Te3thin films showed the amorphous phase. Te and Sb2Te3phases were coexisted in the Sb2Te3-based thin films as the substrate temperature was higher than room temperature. The average grain sizes of the Sb2Te3-based thin films were 39 nm, 45 nm, 62 nm, 84 nm, and 108 nm, as the substrate temperatures were 50°C, 75°C, 100°C, 125°C, and 150°C, respectively. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature; we had found that they were critically dependent on the substrate temperature.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Sarita Boolchandani ◽  
Subodh Srivastava ◽  
Y. K. Vijay

The indium selenium (InSe) bilayer thin films of various thickness ratios, InxSe(1-x) (x = 0.25, 0.50, 0.75), were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Faheem Amin ◽  
Syedah Afsheen Zahra ◽  
Muhammad Sultan ◽  
Sajjad Hussain Mirza ◽  
Fahad Azad

Bilayer thin films of Ge/CdS have been deposited on a glass substrate through thermal evaporation method. The obtained Ge/CdS samples were annealed at temperatures up to 400°C to observe the resulting effect on the structural changes in the film. The bandgap of the annealed films was found to increase with increasing annealing temperature which can be attributed to the increased interlayer diffusion. The interlayer diffusion was found to take effect above a temperature of 300°C which was confirmed by the Rutherford backscattering technique. Complementary XPS was done to investigate the surface stoichiometry of the bilayers.


2013 ◽  
Vol 747 ◽  
pp. 329-332
Author(s):  
Thitinai Gaewdang ◽  
Ngamnit Wongcharoen ◽  
Tiparatana Wongcharoen

CdS thin films were prepared by thermal evaporation onto glass substrate in vacuum better than 5.5x10-5 mbar. The obtained films were subsequently annealed in a pure nitrogen atmosphere at temperature between 100 to 500°C for 30 min. The crystal structure and surface morphology of the as-deposited and annealed films were investigated by XRD and SEM, respectively. Optical band gap and Urbach tail values of the films, determined from spectral transmission data, were found to be slightly varied in the range 2.36-2.40 eV and 110-160 meV, respectively, due to annealing temperature. The refractive index of the films was also evaluated from the spectral transmission data. The dependence of the refractive index on the wavelength obeys the single oscillator model, from which the important parameters such as refractive index, extinction coefficient, oscillator energy (E0) and dispersion energy (Ed) of the films with different annealing temperatures were determined. From the experimental results, the optical parameters of the films are obviously influenced by annealing temperature.


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