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

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

Fabrication and Photoelectrochemical Characterization of Fe, Co, Ni and Cu-Doped TiO2 Thin Films

2013 ◽  
Vol 764 ◽  
pp. 266-283 ◽  
Author(s):  
Ibram Ganesh ◽  
Rekha Dom ◽  
P.H. Borse ◽  
Ibram Annapoorna ◽  
G. Padmanabham ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Metal Ions ◽  
Band Gap ◽  
Metal Ion ◽  
Band Gap Energy ◽  
Chemical Compositions ◽  
Gap Energy ◽  
Glass Substrates ◽  
Photoelectrochemical Characterization

Different amounts of Fe, Co, Ni and Cu-doped TiO2 thin films were prepared on fluorine doped tin oxide (FTO) coated soda-lime glass substrates by following a conventional sol-gel dip-coating technique followed by heat treatment at 550 and 600°C for 30 min. These thin films were characterized for photo-current, chronoamperometry and band-gap energy values. The chemical compositions of metals-doped TiO2 thin films on FTO glass substrates were confirmed by XPS spectroscopic study. The metal-ions doped TiO2 thin films had a thickness of <200 nm="" optical="" transparency="" of="">80%, band-gap energy of >3.6 eV, and a direct band-to-band energy transition. The photoelectrochemical (PEC) studies revealed that all the metal-ions doped TiO2 thin films exhibit n-type semi-conducting behavior with a quite stable chronoamperometry and photo-currents that increase with the increase of applied voltage but decrease with the dopant metal-ion concentration in the thin film. Furthermore, these thin films exhibited flat-band potentials amenable to water oxidation reaction in a PEC cell. The 0.5 wt.% Cu-doped TiO2 thin film electrode exhibited an highest incident photon-to-current conversion efficiency (IPCE) of about 21%.

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

FORMATION OF THE BAND GAP OF CdS THIN FILMS GROWTH BY DIFFERENT TECHNIQUES

2001 ◽  
Vol 15 (17n19) ◽  
pp. 671-674 ◽  
Author(s):  
A. I. OLIVA ◽  
O. SOLÍS-CANTO ◽  
R. CASTRO-RODRÍGUEZ ◽  
P. QUINTANA
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Ultrasonic Vibration ◽  
Band Gap Energy ◽  
Growth Technique ◽  
Optical Window ◽  
Gap Energy ◽  
Glass Substrates ◽  
Cds Thin Films ◽  
Window Effects

We studied the formation of the band gap on CdS thin films deposited on glass substrates by chemical bath deposition (CBD) and close spaced sublimation (CSS) techniques. In order to obtain the first stages of films growth, we used small deposition times for both methods. Films growth by CBD were prepared by two modalities on the bath agitation: magnetic agitation with a magnetic stirrer, and a new proposal based on ultrasonic vibration. Morphological, structural, and optical results were obtained on films. Values of the band gap energy obtained by the absorption method, are agree with the values reported in the literature, but squared absorption coefficient vs. energy curves, showed differences between them. An explanation on this behavior with the optical window effects, the surface roughness, the structural results, the films thickness, and the growth technique is given. CBD technique with ultrasonic vibration produces films with more cleaner surfaces and better optical properties.

scholarly journals Effect of Annealing on Optical Properties of Zinc Oxide Thin Films Prepared by Homemade Spin Coater

2015 ◽  
Vol 15 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Deependra Das Mulmi ◽  
Agni Dhakal ◽  
Buddha Ram Shah
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Band Gap ◽  
Precursor Solution ◽  
Infrared Region ◽  
Band Gap Energy ◽  
Zno Thin Films ◽  
Gap Energy ◽  
Glass Substrates ◽  
Near Ultraviolet

Zinc oxide (ZnO) thin films were deposited on the ordinary glass substrates by spin coating method. The precursor solution was prepared by mixing zinc acetate dehydrate in appropriate proportions with ethanol and diethanolamine (DEA). The obtained thin films were dried at 200°C for 15 minutes in hot air oven. Crystalline ZnO thin films were achieved following annealing process at temperatures 300°, 400° and 500°C for 2 hours. Thin films as- prepared were studied by X-ray diffraction and UV-visible spectroscopy. The films were transparent from near ultraviolet to infrared region. Optical band gap energy of ZnO was obtained 3.22 eV at 300°C. On annealing at 400° and 500°C, band gap energy was shifted at 3.14 eV and 3.05 eV respectively.DOI: http://dx.doi.org/njst.v15i2.12126Nepal Journal of Science and Technology Vol. 15, No.2 (2014) 111-116

scholarly journals Influence of deposition temperature on structural, morphological, and optical properties of ZnS thin films

2018 ◽  
Vol 96 (7) ◽  
pp. 826-830
Author(s):  
Sinan Temel
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Optical Properties ◽  
Band Gap ◽  
Deposition Temperature ◽  
Band Gap Energy ◽  
Complexing Agent ◽  
Gap Energy ◽  
Nanostructured Particles ◽  
Glass Substrates

ZnS thin films were deposited onto glass substrates by chemical bath deposition (CBD) technique at different deposition temperatures (75, 80, 85, 90 °C) with non-toxic complexing agent tri-sodium citrate. Effects of deposition temperature on structural, morphological, and optical properties of thin films were investigated by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet–visible spectroscopy, respectively. The XRD results show that all produced ZnS thin films have cubic structure. The calculated grain size values are between 13 and 26 nm. It was observed that the grain size values increase and crystallization of films improve as the deposition temperature increases. The FESEM images reveal that film surfaces are formed by almost homogeneously dispersed nanostructured particles. Optical characterization results show that ZnS thin films have high transmittance of about 80% in the range of 400–800 nm with band gap energy values between 3.52 and 3.65 eV. As the deposition temperature increases, the band gap energy values increase. According to these results, it was observed that the structural, morphological, and optical properties of ZnS films vary depending on the deposition temperature.

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.

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

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

Preparation and characterization of V2O5 doped SiO2-TiO2 thin films

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Marek Nocuń ◽  
Sławomir Kwaśny
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Gel Technique

AbstractIn our investigation, V doped SiO2/TiO2 thin films were prepared on glass substrates by dip coating sol-gel technique. Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). Transmittance of the samples was characterized using UV-VIS spectrophotometry. Subsequently band-gap energy (Eg) was estimated for these films. Powders obtained from sols were characterized by FTIR spectroscopy. It was found that vanadium decreases optical band gap of SSiO2/TiO2 films.

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