Effect of thickness on the optical properties of Gaas thin films

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

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Effects of Nitrogen Doping on Optical Properties of Tungsten Oxide Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.1773 ◽

2012 ◽

Vol 616-618 ◽

pp. 1773-1777

Author(s):

Xi Lian Sun ◽

Hong Tao Cao

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Tungsten Oxide ◽

Nitrogen Doping ◽

Optical Band Gap ◽

Band Gap Energy ◽

Gap Energy ◽

Tungsten Oxide Thin Films

In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

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

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v7i3.1581 ◽

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

Â Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 â‰¤ x â‰¤ 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 systemâ€™s network.

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Characteristics of Poly(vinyl Alcohol) (PVA) Based Composites Integrated with Green Synthesized Al3+-Metal Complex: Structural, Optical, and Localized Density of State Analysis

Polymers ◽

10.3390/polym13081316 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1316

Author(s):

Shujahadeen B. Aziz ◽

Muaffaq M. Nofal ◽

Hewa O. Ghareeb ◽

Elham M. A. Dannoun ◽

Sarkawt A. Hussen ◽

...

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Metal Complex ◽

Band Gap ◽

Optical Band Gap ◽

Complex Dielectric Constant ◽

Poly Vinyl Alcohol ◽

Optical Parameters ◽

Dispersion Energy ◽

Casting Technique

The influence of dispersing Al-metal complex on the optical properties of PVA was investigated using UV–visible spectroscopy. Polymer composite films with various Al3+-complex amounts in the PVA matrix were arranged by solution casting technique by means of distilled water as a widespread solvent. The formation of Al3+-metal complex was verified through Ultraviolet–visible (UV-Vis) and Fourier-transform infrared spectroscopy (FTIR) examinations. The addition of Al-complex into the polymer matrix led to the recovery of the optical parameters such as dielectric constant (εr and εi) and refractive index (n). The variations of real and imaginary parts of complex dielectric constant as a function of photon wavelength were studied to calculate localized charge density values (N/m*), high-frequency dielectric constant, relaxation time, optical mobility, optical resistivity, and plasma angular frequency (ωp) of electrons. In proportion with Al3+-complex content, the N/m* values were amplified from 3.68 × 1055 kg−1 m−3 to 109 × 1055 kg−1 m−3. The study of optical parameters may find applications within optical instrument manufacturing. The optical band gap was determined from Tauc’s equation, and the type of electronic transition was specified. A remarkable drop in the optical band gap was observed. The dispersion of static refractive index (no) of the prepared composites was analyzed using the theoretical Wemple–DiDomenico single oscillator model. The average oscillator energy (Eo) and oscillator dispersion energy (Ed) parameters were estimated.

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The Optical Performance of Holmium Oxide Doped Tellurite Glass for Potential Optical Fiber

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.317.95 ◽

2021 ◽

Vol 317 ◽

pp. 95-99

Author(s):

Muhammad Noorazlan Abd Azis ◽

Halimah Mohamed Kamari ◽

Suriani Abu Bakar ◽

Azlina Yahya ◽

Umar Saad Aliyu

Keyword(s):

Refractive Index ◽

Band Gap ◽

Tellurite Glass ◽

Optical Band Gap ◽

Band Gap Energy ◽

X Ray Diffraction ◽

Xrd Pattern ◽

Gap Energy ◽

Xrd Method ◽

Nonlinear Pattern

Borotellurite glass had been widely applied in the field of optical communications and devices. In this work, holmium oxides doped borotellurite glass had been successfully fabricated via conventional melt-quenched technique. The structural properties of holmium doped tellurite glass were found using x-ray diffraction (XRD) method. The nonexistence of sharp peaks in XRD pattern shows that the inclusion of holmium tellurite glass leads to the formation long range of disorderness. The optical properties of the glass system such as refractive index and optical band gap energy are investigated using UV-Vis spectrophotometer. The value of refractive index is found in nonlinear trend along with holmium oxides concentration. It is found that the refractive index is more than 2 at 0.01, 0.03 and 0.04 of holmium concentrations. The optical band gap energy was found in similar trend with refractive index which is in nonlinear pattern.

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Effect of Nb doping on morphology, crystal structure, optical band gap energy of TiO2 thin films

Current Applied Physics ◽

10.1016/j.cap.2013.12.025 ◽

2014 ◽

Vol 14 (3) ◽

pp. 421-427 ◽

Cited By ~ 20

Author(s):

Deuk Yong Lee ◽

Ju-Hyun Park ◽

Young-Hun Kim ◽

Myung-Hyun Lee ◽

Nam-Ihn Cho

Keyword(s):

Crystal Structure ◽

Thin Films ◽

Band Gap ◽

Optical Band Gap ◽

Band Gap Energy ◽

Tio2 Thin Films ◽

Gap Energy ◽

Nb Doping

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.710.739 ◽

2012 ◽

Vol 710 ◽

pp. 739-744 ◽

Cited By ~ 1

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.

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Refractive index, band gap energy, dielectric constant and polarizability calculations of ferroelectric Ethylenediaminium Tetrachlorozincate crystal

Journal of Physics and Chemistry of Solids ◽

10.1016/j.jpcs.2015.07.007 ◽

2015 ◽

Vol 86 ◽

pp. 108-113 ◽

Cited By ~ 16

Author(s):

S. Kalyanaraman ◽

P.M. Shajinshinu ◽

S .Vijayalakshmi

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Band Gap ◽

Band Gap Energy ◽

Gap Energy

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Optical Properties of PZT, PLZT, and PNZT Thin Films

MRS Proceedings ◽

10.1557/proc-243-21 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 56

Author(s):

Chien H. Peng ◽

Jhing-Fang Chang ◽

Seshu B. Desu

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Band Gap Energy ◽

Gap Energy ◽

Pzt Films ◽

Direct Band ◽

Band Transition ◽

La Doped

AbstractOptical properties were investigated for undoped, La-doped, and Nd-doped Pb(ZrxTi1-x)O3 thin films deposited on sapphire substrates by metalorganic decomposition (MOD) process. Refractive index and extinction coefficient of these films were calculated from transmission spectra in the wavelength range of 300 to 2000 nm. The packing densities of these films were calculated from the refractive index data by using the effective medium approximation. Band gap energies of these films were also reported under the assumption of direct band-to-band transition. The refractive index and band gap energy of PZT films showed a linear dependence on Zr/Ti ratio. The refractive index decreased, while the band gap energy increased with increasing zirconium content. It was also found that both La-doped and Nd-doped PZT films had higher refractive indices than those of undoped PZT films with the same Zr/Ti ratio (50/50).

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