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

2012 ◽  
Vol 36 (2) ◽  
pp. 233-240 ◽  
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

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

2016 ◽  
Vol 40 (2) ◽  
pp. 179-186 ◽  
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

scholarly journals Studies on the Structural and Optical Properties of AgIn1-XGaXSe2 (0 ≤ x ≤ 1.0) thin Films

1970 ◽  
Vol 33 (2) ◽  
pp. 151-157 ◽  
Author(s):  
FA Chowdhury ◽  
J Begum ◽  
L Quadir ◽  
SM Firoz Hasan
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Transmittance ◽  
Band Gap Energy ◽  
Structural And Optical Properties ◽  
Absorption Region ◽  
Transmittance Spectra ◽  
Gap Energy ◽  
Glass Substrates

Polycrystalline thin films of AgIn1-XGaXSe2 (AIGS) with varying x (0 ≤ x ≤ 1.0) have been grown onto glass substrates by stacked elemental layer (SEL) deposition technique in vacuum (~10-6 mbar). The thickness of the films was kept constant at 500 nm measured on line by frequency shift of quartz crystal. The films were annealed in situ at 300°C for 15 minutes. Structural and optical properties of the films were ascertained by X-ray diffraction (XRD) and UV-VIS-NIR spectrophotometry (photon wavelength ranging between 300 and 2500 nm) respectively. The diffractogram indicates that these films are polycrystalline in nature. The optical transmittance spectra reveal a maximum transmission of 85.91% around 1100 nm of wavelength for x = 0.2. A sharp absorption region is evident from the transmittance spectra that indicate a standard semiconducting nature of the films. The abruptness at the fundamental edge is more distinct in the film with x = 0.2. Optical transmittance, reflectance and thickness of the films were utilized to compute the absorption coefficient, band gap energy and refractive index of the films. The optical band gap is found to be direct-allowed. The band gap energy value, found from this study ranging between 2.3 to 2.4 eV, is very close for different gallium content films. The refractive indices increase almost linearly with photon wavelength range between 1300 and 1500 nm. DOI: 10.3329/jbas.v33i2.4098 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 151-157, 2009

Effect of Thickness on Structural, Morphological, and Optical Properties of Copper (Cu) Doped Zinc Selenide (ZnSe) Thin Films by Vacuum Evaporation Method

2020 ◽  
Vol 43 (2) ◽  
pp. 159-168
Author(s):  
MM Rahman ◽  
C Das ◽  
MM Rahaman ◽  
KMA Hussain ◽  
S Choudhury
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Zinc Selenide ◽  
High Vacuum ◽  
Band Gap Energy ◽  
Cubic Phase ◽  
Thermal Evaporation Method ◽  
Evaporation Method ◽  
Gap Energy ◽  
Znse Thin Films

Effect of thickness on structural, optical and morphological properties of 2% copper (Cu) doped zinc selenide (ZnSe) thin films, grown onto chemically and ultrasonically cleaned glass substrate by thermal evaporation method in high vacuum (~10-6 Torr) were studied. Films of 100, 200, 300 and 400 nm thickness were prepared at 200℃ substrate temperature where annealing temperature and annealing time was fixed at 100℃ and 1 hour respectively. The X-ray diffraction (XRD) exhibited polycrystalline nature indicating the zinc-blende structure with a preferential orientation along the (111) plane of cubic phase. The grain size was found to be 19.27 nm. Dislocation density and microstrain were also found as 2.691 × 10-3 nm-2 and 1.85 × 10-3 respectively. Atomic Force Microscopy (AFM) study confirmed the growth of grains and their distribution over the entire surface of the films. All the films were characterized optically by UV-VIS-NIR spectrophotometer in the photon wavelength ranging from 300 to 1000 nm. The optical transmittance and reflectance were utilized to compute the absorption coefficient, extinction coefficient and band gap energy of the films. The calculated band gap energy was found to increase (2.99 to 3.94 ev) with varying thickness. The maximum transmittance was found to be 87.65% for the 400 nm film. Journal of Bangladesh Academy of Sciences, Vol. 43, No. 2, 159-168, 2019

scholarly journals Optical Properties of Undoped and Indium-doped Tin Oxide Thin Films

2011 ◽  
Vol 35 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Fatema Rezwana Chowdhury ◽  
Shamima Choudhury ◽  
Firoz Hasan ◽  
Tahmina Begum
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Tin Oxide ◽  
Optical Transmittance ◽  
Band Gap Energy ◽  
Visible Range ◽  
Absorption Region ◽  
Gap Energy ◽  
Glass Substrates ◽  
In Doping

Thin films of Tin Oxide (SnO2), having thickness of 200 nm, were formed on to glass substrates by thermal evaporation of high-purity SnO2 powder in vacuum at various substrate temperatures (TS), ranging between 25 and 200°C. SnO2 films with varying thickness were also prepared for a fixed TS = 100°C. Further, doping of SnO2 films with Indium (In) was accomplished through solid state diffusion process by successive deposition of SnO2 and In films and subsequent annealing at 200°C for 10 minutes. Both undoped and doped films were characterized optically by UV-VIS-NIR spectrophotometry in the photon wavelength ranging from 300 to 2500 nm. In the visible photon wavelength range, the average optical transmittance (T%) of the films with varying TS was found to be 85%. The maximum value of T % was found to be 89 % around the wavelength of 700nm. The variation of absorption coefficient with photon energy in the fundamental absorption region is the steepest for TS = 100°C. The sub-band gap (SBG) absorption is also minimum for this Ts. A fluctuating behavior of the band gap energy (Eg) with Ts is observed attaining the highest value of 3.59 eV for Ts = 100°C. The band gap energy increases with thickness but T% in the visible range decreases. The T% in the visible range varies inversely with indium doping, being highest for undoped films. The Eg increases upto 2 wt% In doping and gradually decreases for enhanced doping. It seems reasonable to conclude that In doping does not bring favorable optical characteristics. Undoped SnO2 films having thickness of 200 nm and formed at substrate temperature of 100°C yield essential acceptable properties for photovoltaic applications.DOI: http://dx.doi.org/10.3329/jbas.v35i1.7975Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 99-111, 2011

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

2005 ◽  
Vol 88 (5) ◽  
pp. 1186-1189 ◽  
Author(s):  
Toshio Suzuki ◽  
Piotr Jasinski ◽  
Vladimir Petrovsky ◽  
Harlan U. Anderson
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Band Gap Energy ◽  
Gap Energy

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

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.

Optical Properties of PZT, PLZT, and PNZT Thin Films

1991 ◽  
Vol 243 ◽  
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).

Optical properties and band gap energy of CuInSe2 thin films prepared by two-stage selenization process

2003 ◽  
Vol 64 (9-10) ◽  
pp. 2005-2009 ◽  
Author(s):  
M.V. Yakushev ◽  
A.V. Mudryi ◽  
V.F. Gremenok ◽  
V.B. Zalesski ◽  
P.I. Romanov ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Band Gap Energy ◽  
Two Stage ◽  
Gap Energy ◽  
Selenization Process

scholarly journals Impact of Thickness on the Optical Properties of Selenium Thin Films

2021 ◽  
Vol 25 ◽  
Author(s):  
Shiva Udachan ◽  
Narasimha Ayachit ◽  
Lingappa Udachan ◽  
Raghunanda Halembre
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Film Thickness ◽  
Band Gap ◽  
Optical Density ◽  
Energy Gap ◽  
Band Gap Energy ◽  
Primary Objective ◽  
Gap Energy ◽  
The Impact

Objectives: The primary objective of this investigation is to make a systematic study on the impact of thickness on optical properties, such as energy gap, absorption coefficient, optical density etc., for selenium thin films. Understanding of the band gap energy and its influence on film thickness is of utmost importance in acquiring the intended electrical characterization of semiconducting films. Materials and methods: Ultra-purity selenium (99.99 %) was deposited on glass substrates. During deposition, the glass substrate with its holder were rotated with constant speed to have a smooth coating. Results and discussions: The XRD findings indicate that selenium is amorphous in nature. The optical band gap energy is found to be decreasing form (2.3 to 2eV) with the rise of film thickness in interval (200 to 1000 nm). The band gap energy obeys inverse square law with respect to thickness. Conclusion: We have properly grown thin films of Se below the De Broglie wavelength limit by thermal evaporation in vacuum. The optical density varies directly with film thickness. The absorption coefficients were in the interval (0.5 to 4) × 107m-1. The AFM results confirmed that the Se nano-size increases with the increase in thickness. Both the grain boundaries and sub-grain regions are clearly visible in the SEM micrographs

A Study on Effect of Sol Aging Time on Optical Properties of ZnO Thin Films: Spectroscopic Ellipsometry Method

2019 ◽  
Vol 11 (2) ◽  
pp. 100-108 ◽  
Author(s):  
Ehsan Motallebi Aghkonbad ◽  
Maryam Motallebi Aghgonbad ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Aging Time ◽  
Imaginary Part ◽  
Spectroscopic Ellipsometry ◽  
Annealing Temperature ◽  
Band Gap Energy ◽  
Zno Thin Films ◽  
Gap Energy

Background: Due to wide band gap and large excitonic binding energy, being inexpensive, abundance in nature and easy synthesis ZnO is a promising candidate in many applications such as solar cells. Experimental: In the current work a series of ZnO thin films were deposited on glass substrates using sol-gel method to investigate the change in optical behavior of the film with sol aging time (asprepared, 8, 16, 24 and 32 hours) and the annealing temperature (300ᵒC and 500ᵒC). The optical properties of thin films were explored using spectroscopic ellipsometry method including the real and imaginary part of refractive index, real and imaginary part of dielectric function and band gap energy of the layers in the 300-900 nanometer wavelength range. Results: It can be deduced from the results that sol aging time and annealing temperature, affect the optical properties of the samples. Using single oscillator energy model of Wemple and Di Domenico parameters such as free charge carrier concentration ratio to effective mass, and plasma frequency, were calculated. Conclusion: The films prepared using 24 h aged solution, had the highest transmittance and the largest band gap energy.

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