scholarly journals Bandgap Engineering of Bilayer Ge/CdS Thin Films via Interlayer Diffusion under Different Annealing Temperatures

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Faheem Amin ◽  
Syedah Afsheen Zahra ◽  
Muhammad Sultan ◽  
Sajjad Hussain Mirza ◽  
Fahad Azad
Keyword(s):  
Thin Films ◽  
Glass Substrate ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Rutherford Backscattering ◽  
Bandgap Engineering ◽  
Thermal Evaporation Method ◽  
Annealing Temperatures ◽  
Cds Thin Films

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.

Effect of Annealing Temperature on the Optical Parameters of CdS Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 747 ◽  
pp. 329-332
Author(s):  
Thitinai Gaewdang ◽  
Ngamnit Wongcharoen ◽  
Tiparatana Wongcharoen
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Optical Parameters ◽  
Spectral Transmission ◽  
Dispersion Energy ◽  
Thermal Evaporation Method ◽  
Transmission Data ◽  
Cds Thin Films

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.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

Structural Properties of PbI2 Thin Film

2014 ◽  
Vol 879 ◽  
pp. 175-179 ◽  
Author(s):  
Safaa I. Mohammed ◽  
Naser Mahmoud Ahmed ◽  
Y. Al-Douri ◽  
U. Hashim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Analysis ◽  
Film Thickness ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Lead Iodide ◽  
Thermal Evaporation Method ◽  
Growth Orientation

Lead iodide (PbI2) thin films were successfully prepared by thermal evaporation method on a glass substrate at room temperature. The structural analysis of these films was done by XRD. The results revealed that the crystallite size increases when increasing the film thickness and annealing temperature. In addition, the preferred growth orientation was 001 for all the samples.

Structural and Optical Properties of Multilayer Heterostructure of CdTe/CdSe Thin Films

2019 ◽  
Vol 233 (9) ◽  
pp. 1215-1231 ◽  
Author(s):  
Farzana Majid ◽  
Abdul Malik ◽  
Sadia Ata ◽  
Zaheer Hussain ◽  
Ismat Bibi ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Visible Region ◽  
Xrd Analysis ◽  
Band Alignment ◽  
Phonon Modes ◽  
Structural And Optical Properties ◽  
Thermal Evaporation Method ◽  
Multilayer Heterostructures

Abstract CdTe/CdSe multilayer heterostructures thin films were prepared by thermal evaporation method. The CdTe/CdSe layers deposited on glass substrate and effects of annealing temperature on optical and structural properties of thin films were investigated. The XRD analysis revealed that CdTe and CdSe were in cubic (111) and hexagonal (100) forms. By increasing the annealing temperature, intensity of XRD peaks increased for multilayer heterostructures. Band alignment in heterostructures of CdTe/CdSe was of type II. Energy band gaps values for CdTe/CdSe multilayer heterostructures increased with respect to bulk compounds. During emission, red and blue shifts are observed in visible region in photoluminescence spectrum of CdTe/CdSe samples. Due to better crystallinity of multilayer thin film, 1LO, 2LO and 3LO phonon modes were observed in Raman spectrum.

Optical Properties of Cadmium Sulphide (CdS) Thin Films Spin-Coated on Glass Substrates

2021 ◽  
Vol 14 (1) ◽  
pp. 49-58
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Extinction Coefficient ◽  
Spin Coating ◽  
Glass Substrate ◽  
Annealing Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sem Image ◽  
Cds Thin Films

Abstract: CdS thin films were synthesized on a glass substrate using spin coating method. The effects of annealing temperature on the optical properties of the prepared CdS films were investigated for different annealing temperatures of 200, 300 and 400 °C. Cadmium acetate, thiourea and ammonia were used as the source materials for the preparation of the thin films. The elemental composition, morphological, optical and structural properties of the films obtained by spin coating were investigated using Energy Dispersive X- ray Spectroscopy (EDAX), Scanning Electron Microscope (SEM), UV Spectrophotometry and X-ray diffraction (XRD) respectively. The SEM image of the unannealed film shows a spherical morphology and an irregular pattern without any void. It also shows that the film covers the substrate well. Annealing leads to an increase in transmittance with the highest transmission of 87% observed for the film annealed at 400oC. With increase in annealing temperature, optical parameters like extinction coefficient and dielectric constants show a reduction, while refractive index and skin depth exhibit an improvement. The absorption coefficient increases with increasing photon energy in the range 3.6 to 4.0 eV. The band gap values of the CdS thin film samples were found to be in the range between 3.14 eV and 3.63 eV. The bandgap is somewhat greater than the value of bulk CdS due to quantum size effect. EDX image confirmed the presence of Cadmium and Sulphur in the prepared CdS films. Annealing did not significantly change the extinction coefficient. The X-ray diffraction confirms the cubic structure of CdS deposited on glass substrate, where reflections from (111), (200), (220) and (311) planes are clearly shown with a preferential orientation along (111) plane. Debye-Scherer equation was used to determine the crystallite size of the most intense plane (111) and the value was found to be 8.4 nm. Keywords: SEM image, Spin coating, Surface morphology, Optical properties, Annealing.

Effect of annealing temperature on thermoelectric properties of zinc nitride thin films grown by thermal evaporation method

2020 ◽  
Vol 46 (16) ◽  
pp. 25992-25995
Author(s):  
Hassnain Zaman ◽  
Jolly Jacob ◽  
Khurram Mehboob ◽  
K. Mahmood ◽  
U. Rehman ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermoelectric Properties ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Evaporation Method ◽  
Zinc Nitride

scholarly journals Effect of Annealing Temperature on The Some Electrical Properties of InSb:Bi Thin Films

2010 ◽  
Vol 7 (4) ◽  
pp. 1416-1420
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Thermoelectric Power ◽  
Carrier Concentration ◽  
Glass Substrate ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Technique ◽  
Evaporation Technique

InSb alloy was prepared then InSb:Bi films have been prepared successfully by thermal evaporation technique on glass substrate at Ts=423K. The variation of activation energies(Ea1,Ea2)of d.c conductivity with annealing temperature (303, 373, 423, 473, 523 and 573)K were measured, it is found that its values increases with increasing annealing temperature. To show the type of the films, the Hall and thermoelectric power were measured. The activation energy of the thermoelectric power is much smaller than for d.c conductivity and increases with increasing annealing temperature .The mobility and carrier concentration has been measured also.

Annealing Effect on the Optical Properties of Multi Walled Carbon Nano Tube Doped Cu5Se75Ge10In10 Thin Films Prepared by Thermal Evaporation Method

2020 ◽  
Vol 12 (1) ◽  
pp. 78-82
Author(s):  
Surabhi Mishra ◽  
Priyanka Jaiswal ◽  
Pooja Lohia ◽  
D. K. Dwivedi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Bulk Sample ◽  
Optical Data ◽  
Thermal Evaporation Method ◽  
Glassy Alloys ◽  
Different Temperatures ◽  
Evaporation Technique

The optical properties of as prepared and annealed [(Cu5Se75Ge10In10)99 (CNT)1] thin films deposited with thermal evaporation technique has been discussed as a function of photon energy in wavelength range 300–900 nm in present paper. The bulk sample of as prepared glassy alloys were developed using the melt quench technique. Thin films of prepared glassy alloys were deposited on a glass substrate with thermal evaporation unit at room temperature at base pressure of ∼10–5 Pa. The films were annealed at two different temperatures between glass transition temperature and crystallization temperatures. Analysis of the optical data shows that optical bandgap decreases with increasing annealing temperature while extinction coefficient, absorption coefficient and transmission shows increasing behaviour with increase in annealing temperature.

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