Synthesis, Optical, Chemical and Thermal Characterizations of PMMA-PS/CeO2 Nanoparticles Thin Film

We report the synthesis of hybrid thin films based on polymethyl methacrylate) (PMMA) and polystyrene (PS) doped with 1%, 3%, 5%, and 7% of cerium dioxide nanoparticles (CeO2 NPs). The As-prepared thin films of (PMMA-PS) incorporated with CeO2 NPs are deposited on a glass substrate. The transmittance T% (λ) and reflectance R% (λ) of PMMA-PS/CeO2 NPs thin films are measured at room temperature in the spectral range (250–700) nm. High transmittance of 87% is observed in the low-energy regions. However, transmittance decreases sharply to a vanishing value in the high-energy region. In addition, as the CeO2 NPs concentration is increased, a red shift of the absorption edge is clearly observed suggesting a considerable decrease in the band gap energy of PMMA-PS/CeO2 NPs thin film. The optical constants (n and k) and related key optical and optoelectronic parameters of PMMA-PS/Ce NPs thin films are reported and interpreted. Furthermore, Tauc and Urbach models are employed to elucidate optical behavior and calculate the band gaps of the as-synthesized nanocomposite thin films. The optical band gap energy of PMMA-PS thin film is found to be 4.03 eV. Optical band gap engineering is found to be possible upon introducing CeO2 NPs into PMMA-PS polymeric thin films as demonstrated clearly by the continuous decrease of optical band gap upon increasing CeO2 content. Fourier-transform infrared spectroscopy (FTIR) analysis is conducted to identify the major vibrational modes of the nanocomposite. The peak at 541.42 cm−1 is assigned to Ce–O and indicates the incorporation of CeO2 NPs into the copolymers matrices. There were drastic changes to the width and intensity of the vibrational bands of PMMA-PS upon addition of CeO2 NPs. To examine the chemical and thermal stability, thermogravimetric (TGA) thermograms are measured. We found that (PMMA-PVA)/CeO2 NPs nanocomposite thin films are thermally stable below 110 °C. Therefore, they could be key candidate materials for a wide range of scaled multifunctional smart optical and optoelectronic devices.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.764.266 ◽

2013 ◽

Vol 764 ◽

pp. 266-283 ◽

Cited By ~ 8

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%.

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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 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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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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Fabrication of Cu2ZnSnS4 Thin Films Based on Facile Nanocrystals-Printing Approach with Rapid Thermal Annealing (RTA) Process

Coatings ◽

10.3390/coatings9020130 ◽

2019 ◽

Vol 9 (2) ◽

pp. 130 ◽

Cited By ~ 1

Author(s):

Jin Chen ◽

Fengchao Wang ◽

Bobo Yang ◽

Xiaogai Peng ◽

Qinmiao Chen ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Band Gap ◽

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Band Gap Energy ◽

Czts Thin Film ◽

Gap Energy ◽

Thermal Solution ◽

Absorbing Layer

In the current study, Cu2ZnSnS4 (CZTS) thin film was successfully fabricated by the facile nanocrystals (NCs)-printing approach combined with rapid thermal annealing (RTA) process. Firstly, the CZTS NCs were synthesized by a thermal solution method and the possible formation mechanism was analyzed briefly. Then the influences of RTA toleration temperature and duration time on the various properties of as-printed thin films were examined via XRD, Raman, FE-SEM, UV-vis-IR spectroscopy, EDS and XPS treatments in detail. As observed, the RTA factors of temperature and time had significant impacts on the structure and morphology of as-prepared thin films, while there were no obvious effects on the band gap energy in studied conditions. The results showed that the obtained thin film at optimal RTA conditions of (600 °C, 20 min) featured a kesterite structure in pure phase and an irregular morphology consisting of large grains. Moreover, the satisfactory composition of a Cu-poor, Zn-rich state and an ideal band gap energy of 1.4 eV suggests that as-fabricated CZTS thin film is a suitable light-absorbing layer candidate for the application in thin film solar cells.

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