Optical Properties of PZT, PLZT, and PNZT Thin Films

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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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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Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200201 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20402

Author(s):

Kaoutar Benthami ◽

Mai ME. Barakat ◽

Samir A. Nouh

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Color Difference ◽

Band Gap Energy ◽

Polybutylene Terephthalate ◽

Γ Irradiation ◽

Gap Energy ◽

Vis Spectroscopy ◽

Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

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Effect of thickness on the optical properties of Gaas thin films

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v37i1.15684 ◽

2013 ◽

Vol 37 (1) ◽

pp. 83-91 ◽

Cited By ~ 13

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

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Effect of Doping Concentration on the Optical Properties of Indium-Doped Gallium Arsenide Thin FILMS

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v40i2.30773 ◽

2016 ◽

Vol 40 (2) ◽

pp. 179-186 ◽

Cited By ~ 1

Author(s):

Md Saiful Islam ◽

Chitra Das ◽

Mehnaz Sharmin ◽

Kazi Md Amzad Hussain ◽

Shamima Choudhury

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Doping Concentration ◽

High Vacuum ◽

Band Gap Energy ◽

Crystal Thickness ◽

Thermal Evaporation Method ◽

Gap Energy ◽

Indium Doping

Effects of indium doping (concentration 0.2, 0.3 and 0.4%) on the optical properties of GaAs thin films were studied. Thin films of 600 nm were grown onto chemically and ultrasonically cleaned glass substrate by thermal evaporation method in high vacuum (~10-4 Pa) at 50°C fixed substrate temperature. The samples were annealed for 15 minutes at a fixed temperature of 200°C. The thicknesses of films were being measured in situ by a quartz crystal thickness monitor during deposition. The transmittance and reflectance data were found using UV-VIS-NIR spectrophotometer in the photon wavelength range of 310 ~ 2500 nm. These data were utilized to compute the absorption coefficient, refractive index, extinction co-efficient and band gap energy of the studied films. Here transmittance was found 78 for 0.2% indium doping concentration. The band gap energy decreased with the increase of doping concentration.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 2, 179-186, 2016

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Properties of CdS Thin Films Grown by Chemical Bath Deposition as a Function of Bath Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.609.243 ◽

2009 ◽

Vol 609 ◽

pp. 243-247 ◽

Cited By ~ 1

Author(s):

H. Moualkia ◽

S. Hariech ◽

M.S. Aida

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Chemical Bath Deposition ◽

Bath Temperature ◽

Band Gap Energy ◽

X Ray Diffraction ◽

Glass Substrates ◽

Cds Thin Films ◽

Direct Band

The present work deals with the preparation and characterization of cadmium sulfur (CdS) thin films. These films are prepared by chemical bath deposition on the well cleaned glass substrates. The thickness of the samples was measured by using profilometer DEKTAK, structural and optical properties were studied by X-ray diffraction analysis, and UV-visible spectrophotometry. The optical properties of the films have been investigated as a function of temperature. The band gap energy and Urbach energy were also investigated as a function of temperature. From the transmittance data analysis the direct band gap ranges from 2.21 eV to 2.34 eV. A dependence of band gap on temperature has been observed and the possible raisons are discussed. Transmission spectra indicates a high transmission coefficient (75 %). Structural analysis revealed that the films showed cubic structure, and the crystallite size decreased at a higher deposition temperature.

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The Optical Properties and Band Gap Energy of Nanocrystalline La0.4Sr0.6TiO3 Thin Films

Journal of the American Ceramic Society ◽

10.1111/j.1551-2916.2005.00216.x ◽

2005 ◽

Vol 88 (5) ◽

pp. 1186-1189 ◽

Cited By ~ 5

Author(s):

Toshio Suzuki ◽

Piotr Jasinski ◽

Vladimir Petrovsky ◽

Harlan U. Anderson

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Band Gap Energy ◽

Gap Energy

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Optical Properties of CuZn0.8Cd0.2SnS4 Quinternary Alloy Nanostructures

Volume 6B: Energy ◽

10.1115/imece2015-50212 ◽

2015 ◽

Author(s):

A. S. Ibraheam ◽

Y. Al-Douri ◽

U. Hashim ◽

Waleed K. Ahmed

Keyword(s):

Optical Properties ◽

Band Gap ◽

Spin Coating ◽

Band Gap Energy ◽

Direct Band Gap ◽

Gap Energy ◽

Coating Technique ◽

Cu Content ◽

Direct Band ◽

Alloy Nanostructures

Cu2Zn0.8Cd0.2SnS4 quinternary alloy nanostructures were prepared with different copper (Cu) concentrations; 0.3, 0.5, 0.7 and 0.9 mol/L using the spin coating technique. The direct band gap energy of Cu2Zn0.8Cd0.2SnS4 quinternary alloy nanostructures is investigated to decrease as Cu increases. The transmittance value in the range 63–49% is depending on Cu content.

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Substrate Temperature Effect on the Structural and Optical Properties of Znse Thin Films

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v36i2.12969 ◽

2012 ◽

Vol 36 (2) ◽

pp. 233-240 ◽

Cited By ~ 5

Author(s):

M R A Bhuiyan ◽

M A H Miah ◽

J Begum

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Optical Transmittance ◽

Lattice Parameter ◽

Band Gap Energy ◽

Thermal Evaporation Method ◽

Gap Energy ◽

Znse Thin Films ◽

Average Lattice

Zinc selenide (ZnSe) thin films were deposited on to chemically and ultrasonically cleaned glass substrates at different substrate temperatures from room temperature to 200°C keeping the thickness fixed at 300 nm by using thermal evaporation method in vacuum. The structural properties of the films were ascertained by X-ray diffraction (XRD) method utilizing a diffractometer. The optical properties were measured in the photon wavelength ranging between 300 and 2500 nm by using a UV-VIS-NIR spectrophotometer. The XRD patterns reveal that the films were polycrystalline in nature exhibiting f.c.c zincblende structure with average lattice parameter, a = 5.6873Å. The grain size, strain and dislocation densities of the films have bee calculated. The optical transmittance and reflectance were utilized to compute the absorption coefficient, band gap energy and refractive index of the films. The band gap energy of the films was extracted from the absorption spectra. The direct band gap energy of the films slightly increases with substrate temperature.DOI: http://dx.doi.org/10.3329/jbas.v36i2.12969Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 233-240, 2012

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