scholarly journals Analysis of AC-Conductivity in Chalcogenide Ge10Se20 Bi80Thin Film

2016 ◽  
Vol 13 (2) ◽  
pp. 110-115 ◽  
Author(s):  
Shiveom Srivastav
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Conduction Mechanism ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Melt Quenching ◽  
Thermal Evaporation Method ◽  
Correlated Barrier Hopping ◽  
Dominant Conduction Mechanism

The alloy Ge10Se20 Bi80 has been prepared. Thin films of Ge10Se20 Bi80 has been prepared via a thermal evaporation method (melt quenching technique) with 3000A thickness, and rate of deposition (4.1) A/sec at pressure 2x10-5 Torr. The A.C electrical conductivity of a- thin films Ge10Se20 Bi80 has been studied as a function of frequency for annealing temperature within the range (423-623) K, the deduced exponent s values, was found to decrease with increasing of annealing temperature through the frequency of the range (102-106) Hz. It was found that, the correlated barrier hopping (CBH) is the dominant conduction mechanism. Values of dielectric constant ε1 and dielectric loss ε2 were found to decrease with frequency and increase with temperature. The activation energies have been calculated for the annealed thin films.

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.

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.

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.

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 723-729 ◽  
Author(s):  
D. NITHYAPRAKASH ◽  
B. PUNITHAVENI ◽  
J. CHANDRASEKARAN
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Ac Conductivity ◽  
Thermal Evaporation ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Cbh Model ◽  
X Ray ◽  
Correlated Barrier Hopping ◽  
Tan Δ

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.

scholarly journals Study the Band Energy Structure and Absorption Coefficient for PbSe Thin Films

2008 ◽  
Vol 5 (1) ◽  
pp. 89-94
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Energy Structure ◽  
Density Of State ◽  
Melt Quenching ◽  
Reflection And Transmission ◽  
Thermal Evaporation Method ◽  
Localized State

The PbSe alloy was prepared in evacuated quarts tubs by the method of melt quenching from element, the PbSe thin films prepared by thermal evaporation method and deposited at different substrate temperature (Ts) =R.T ,373 and 473K . The thin films that deposited at room temperature (R.T=303)K was annealed at temperature, Ta= R.T, 373 and 473K . By depended on D.C conductivity measurements calculated the density of state (DOS), The density of extended state N(Eext) increases with increasing the Ts and Ta, while the density of localized state N(Eloc) is decreased . We investigated the absorption coefficient (?) that measurement from reflection and transmission spectrum result, and the effect of Ts and Ta on it , also we calculated the tail width for each prepared films.

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.

scholarly journals Effect of thickness on the structure, morphology and A.C conductivity of Bi2S3 thin films

2019 ◽  
Vol 15 (33) ◽  
pp. 87-95
Author(s):  
Bushra A. Hasan
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Thermal Evaporation ◽  
Amorphous Structure ◽  
Bismuth Sulfide ◽  
Thermal Evaporation Method ◽  
Structure And Morphology ◽  
Structure Morphology ◽  
Average Grain Size ◽  
Diffraction Peaks

Thin films samples of Bismuth sulfide Bi2S3 had deposited onglass substrate using thermal evaporation method by chemicalmethod under vacuum of 10-5 Toor. XRD and AFM were used tocheck the structure and morphology of the Bi2S3 thin films. Theresults showed that the films with law thickness <700 nm were freefrom any diffraction peaks refer to amorphous structure while filmswith thickness≥700 nm was polycrystalline. The roughness decreaseswhile average grain size increases with the increase of thickness. TheA.C conductivity as function of frequency had studied in thefrequency range (50 to 5x106 Hz). The dielectric constant,polarizability showed significant dependence upon the variation ofthickness.

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
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