scholarly journals Effect of Ge Addition on the Optical Band Gap and Refractive Index of Thermally Evaporated Thin Films

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Pankaj Sharma ◽  
S. C. Katyal
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Band Gap ◽  
Density Of States ◽  
Spectral Range ◽  
Transmission Spectrum ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Thermal Evaporation Technique ◽  
Evaporation Technique

The present paper reports the effect of Ge addition on the optical band gap and refractive index of thin films. Thin films of and were prepared by thermal evaporation technique at base pressure  Pa. Optical band gap and refractive index were calculated by analyzing the transmission spectrum in the spectral range 400–1500 nm. The optical band gap decreases while the refractive index increases with the addition of Ge to . The decrease of optical band gap has been explained on the basis of density of states; and the increase in refractive index has been explained on the basis increase in disorder in the system.

Electrical conductivity studies of mixed phthalocyanine thin films

Open Physics ◽  
2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Abraham Varghese ◽  
C. Menon
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Copper Phthalocyanine ◽  
Thermal Evaporation Technique ◽  
Nickel Phthalocyanine ◽  
Mixed Films ◽  
Evaporation Technique

AbstractThin films of mixed of Copper Phthalocyanine (CuPc) and Nickel Phthalocyanine (NiPc) are deposited onto a pure glass substrate by a simultaneous thermal evaporation technique at room temperature. The material D.C. electrical conductivity of films at room temperature and also films annealed at 523 K has been investigated. The optical absorption and band gaps of the films are also measured. The results show that the electrical resistance is lower for the mixed films compared with the pure samples and also the optical band gap decreases for the mixed samples compared to the pure samples.

Optical Investigations of In2Se2.7Sb0.3 Thin Films Prepared by Thermal Evaporation Technique

2019 ◽  
Vol 969 ◽  
pp. 355-360 ◽  
Author(s):  
Piyush Patel ◽  
Vimal Patel ◽  
Sandip Vyas ◽  
Jaydev Patel ◽  
Himanshu Pavagadhi
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Radiation Detectors ◽  
Thermal Evaporation Technique ◽  
Clean Glass Substrate ◽  
Amorphous Nature ◽  
Evaporation Technique

The III-VI compound semiconductors are important for the fabrication of ionizing radiation detectors, solid-state electrodes, and photosensitive heterostructures, solar cell as well as ionic batteries. In this paper, In2Se2.7Sb0.3 thin films have been grown by thermal evaporation technique onto a with chemically clean glass substrate. Amorphous nature of the films has been discovered by UV-VIS spectrophotometer. The analysis by absorption spectra within the spectral range 200nm -900 nm has been used for the optical characterization of thin films. From these data the optical constants (absorption coefficient (α), refractive index (η), extinction coefficient (k)) and optical band gap (Eg) are studied. The results were discussed, and reported in detail.

scholarly journals Laser Irradiation Effect on the Optical Band Gap of Se96-xTe4Hgx Thin Films

2016 ◽  
Vol 1 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Adam A Bahishti ◽  
Islam Uddin ◽  
M Zulfequar ◽  
T Alharbi
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Laser Irradiation ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Irradiation Time ◽  
Irradiation Effect ◽  
Evaporation Technique ◽  
Induced Defects ◽  
Irradiation Induced Defects

The effect of laser irradiation on the optical band gap of Se96-xTe4Hgx thin films has been studied. Thin films of thickness 300 nm have been deposited on glass substrate by using thermal evaporation technique. The result shows that irradiation causes a red shift in the absorption edge and hence optical band gap decreases with increasing irradiation time. The results have been analyzed on the basis of laser irradiation-induced defects in the film. Furthermore, optical band gap has found to decrease by increasing mercury concentration and optical band gap decreases rapidly with a higher concentration of mercury.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

scholarly journals Effect of thickness on the optical properties of Gaas thin films

2013 ◽  
Vol 37 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Chitra Das ◽  
Jahanara Begum ◽  
Tahmina Begum ◽  
Shamima Choudhury
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Band Gap ◽  
Optical Band Gap ◽  
Visible Region ◽  
Solar Spectrum ◽  
Band Gap Energy ◽  
Optical Parameters ◽  
Gap Energy

Effect of thickness on the optical and electrical properties of gallium arsenide (GaAs) thin films were studied. The films of different thicknesses were prepared by vacuum evaporation method (~10-4 Pa) on glass substrates at a substrate temperature of 323 K. The film thickness was measured in situ by a frequency shift of quartz crystal. The thicknesses were 250, 300 and 500 nm. Absorption spectrum of this thin film had been recorded using UV-VIS-NIR spectrophotometer in the photon wavelength range of 300 - 2500 nm. The values of some important optical parameters of the studied films (absorption coefficient, optical band gap energy and refractive index; extinction co-efficient and real and imaginary parts of dielectric constant) were determined using these spectra. Transmittance peak was observed in the visible region of the solar spectrum. Here transmittance showed better result when thicknesses were being increased. The optical band gap energy was decreased by the increase of thickness. The refractive index increased by increasing thickness while extinction co-efficient and real and imaginary part of dielectric constant decreased. DOI: http://dx.doi.org/10.3329/jbas.v37i1.15684 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 1, 83-91, 2013

Investigative Study of Optical Parameters of Se80.5Bi1.5Te18-yAgy Thin Films

2012 ◽  
Vol 710 ◽  
pp. 739-744 ◽  
Author(s):  
Anup Kumar ◽  
Pawan Heera ◽  
P. B Baraman ◽  
Raman Sharma
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Integrated Circuits ◽  
Band Gap ◽  
Communication Systems ◽  
Optical Band Gap ◽  
Optical Parameters ◽  
Optical Integrated Circuits ◽  
Increase With Increase ◽  
Good Transparency

The optical constants, like absorption coefficient (α), optical band gap (Eg) and refractive index (n), in Se80.5Bi1.5Te18-yAgy (y= 0, 1.0 and1.5) thin films are calculated using well known Swanepoel’s method in the spectral range of 600-2000 nm. The optical band gap has been estimated by using Tauc’s extrapolation method and is found to increase with increase in Ag content. The present results shows that the large value of nonlinear refractive index and good transparency of these thin films will make them a very promising materials for optical integrated circuits in the optical communication systems.

Ellipsometric analysis of Cd1−xZnxSe thin films prepared by a thermal evaporation technique

2011 ◽  
Vol 83 (6) ◽  
pp. 065706 ◽  
Author(s):  
Arshad Mahmood ◽  
Shaista R ◽  
A Shah ◽  
U Aziz ◽  
E Ahmed ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Evaporation ◽  
Thermal Evaporation Technique ◽  
Evaporation Technique
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