Band-gap energies of sol-gel-derived SrTiO3 thin films

2001 ◽  
Vol 79 (23) ◽  
pp. 3767-3769 ◽  
Author(s):  
Dinghua Bao ◽  
Xi Yao ◽  
Naoki Wakiya ◽  
Kazuo Shinozaki ◽  
Nobuyasu Mizutani
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Sol Gel

The effect of the withdrawal speed on properties of nickel oxide thin films

2019 ◽  
Vol 234 (10) ◽  
pp. 647-655
Author(s):  
Zohra Nazir Kayani ◽  
Atiqa Aslam ◽  
Rabia Ishaque ◽  
Syeda Nosheen Zahra ◽  
Hifza Hanif ◽  
...  
Keyword(s):  
Thin Films ◽  
Nickel Oxide ◽  
Band Gap ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Dip Coating ◽  
Oxide Thin Films ◽  
Withdrawal Speed ◽  
Sem Micrograph ◽  
Nickel Oxide Thin Films

Abstract Nickel oxide thin films have been prepared by sol-gel dip-coating technique on glass substrate. It is shown that nickel oxide thin films have poly crystalline nature. Nickel oxide thin films exhibit high transmission (39–85%) in the wavelength range of 400–900 nm, strong absorption between 300 and 400 nm wavelengths and decrease of band gap values are in the range 3.69–3.27 eV with increase of withdrawal speed. High band gap at low withdrawal speed is because of the small average crystallite size, which decreases with increase in withdrawal speed. The SEM micrograph shows cubic crystallites and surface of thin films become dense, smooth and homogeneous with an increase in withdrawal speed. Assessment of nickel oxide deposition conditions provides gateway for effective and cheap solar cells.

scholarly journals Correlation of film thickness to optical band gap of Sol-gel derived Ba0.9Gd0.1TiO3 thin films for optoelectronic applications

2017 ◽  
Vol 162 ◽  
pp. 01042
Author(s):  
Yen Chin Teh ◽  
Ala’eddin A. Saif ◽  
Zul Azhar Zahid Jamal ◽  
Prabakaran Poopalan
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Optoelectronic Applications

Influence of doping precursor on band gap and morphologies of sol-gel deposited ZnMgO thin films

2014 ◽  
Vol 11 (9-10) ◽  
pp. 1488-1492 ◽  
Author(s):  
Amanpal Singh ◽  
Sonia Saini ◽  
Dinesh Kumar ◽  
P. K. Khanna ◽  
Mukesh Kumar ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Sol Gel

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.

Band-Gap Engineering Based on Ti@ZnO Nanocolloids: Tunable Optical Properties

2014 ◽  
Vol 617 ◽  
pp. 161-165
Author(s):  
Chrystelle Neaime ◽  
Fabien Grasset ◽  
Tangi Aubert
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Uv Light ◽  
Sol Gel ◽  
Wide Band ◽  
Colloidal Solutions ◽  
Light Emitters ◽  
Wide Range ◽  
High Concentrations ◽  
Acoustic Wave Devices

One of the largest application areas of sol-gel chemistry is thin-film preparation. Using this approach, we started to synthesize M@ZnO colloidal solutions for the preparation of functional thin films. ZnO is a wide band-gap (3.37 eV) semiconductor with large exciton binding energy. In the bulk or in nanosized form, it could be used in a wide range of applications such as UV light emitters, spin functional devices, gas sensors, transparent electronics or surface acoustic wave devices. Since recently, the preparation of innovative functional M@ZnO materials by doping or functionalizing nanocolloids constitutes a new challenge. Using high concentrations of the different Ti@ZnO nanocolloids, we were able to prepare various functional colloidal solutions with tunable emission and thin films, such as red-luminescent Eu3+@ZnTiO3 or versatile ZnTiON colored nanomaterials.

Photoluminescence and Electroluminescence Properties of (Ca,Sr)TiO3:Er

2016 ◽  
Vol 698 ◽  
pp. 60-65 ◽  
Author(s):  
Tôru Kyômen ◽  
Miyu Seki ◽  
Minoru Hanaya ◽  
Hiroshi Takashima
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Band Gap ◽  
Solid State Reaction ◽  
Spin Coating ◽  
Sol Gel ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Powder Samples ◽  
Coating Methods

Powder samples of (Ca,Sr)TiO3:Er were prepared by a solid-state reaction method. Photoluminescence due to f-f transitions of Er3+ was not induced by band-gap excitation of (Ca,Sr)TiO3 but by f-f transitions of Er3+. An electroluminescent device in which thin films of Ca0.6Sr0.4TiO3:Er and SnO2:Sb are stacked alternately was prepared by sol-gel and spin-coating methods. Very weak electroluminescence due to f-f transition of Er3+ was observed in the device.

scholarly journals Fabrication of Tantalum Oxyfluoride and Oxynitride Thin Films via Ammonolysis of Sol-Gel Processed Tetraethoxo (β-diketonato) Tantalum (V) Precursors for Enhanced Photocatalytic Activity

2021 ◽  
Author(s):  
Mohammad Danish ◽  
Ashutosh Pandey ◽  
Aftab Aslam Parwaz Khan ◽  
Abdullah M Asiri
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Present Report ◽  
Sol Gel ◽  
Blue Dye ◽  
Undoped Film ◽  
H Nmr ◽  
Elemental Analyses ◽  
Band Gap Narrowing

Abstract In the present report, the generation of Tantalum oxyfluoride and oxynitride upon ammonolysis of the gel obtained from modified tantalum-alkoxo complexes is reported. To the best of our knowledge, this is first report of the formation of tantalum oxyfluoride thin films via ammonolysis of the β-diketone modified tantalum-alkoxo complex [Ta(OEt)4(CF3COCH2COCH3)]m. The integration of nitrogen and fluorine in lattice sites of metal oxides leads to significant reduction in the band gap, resulting in their activation under visible light. Moreover, in this report the effect of the modified alkoxide precursors and ammonolysis on the photo-physical properties of Ta2O5 thin films have also been investigated and compared with the results obtained from films fabricated from unmodified tantalum (V) ethoxide. 1H NMR, 13C NMR and elemental analyses confirmed successful modification of tantalum (V) ethoxide to [Ta(OCH2CH3)4(CH3COCHClCOCH3)]m (1), [Ta(OCH2CH3)4(CF3COCH2COCH3]m (2) and [Ta(OCH2CH3)4 (CH3COC(CH3)2COCH3))]m (3). The fabrication of Ta2O5 thin films involved the spin casting of the gels of modified tantalum alkoxo complexes (processed by sol-gel method) on to glass substrate. X-ray photoelectron spectroscopy results show that nitrogen was incorporated into the ammonolyzed films fabricated from complex precursors (1) and (3), while the presence of fluorine as tantalum oxyfluoride was confirmed in the ammonolyzed film fabricated from complex (2) precursor. The optical characterization insinuate band gap narrowing from 3.55 eV for undoped film prepared from tantalum (V) ethoxide to 3.47 eV for undoped film prepared from [Ta(OEt)4(CF3COCH2COCH3)]m and 3.05 eV for ammonolyzed film obtained from [Ta(OEt)4(CF3COCH2COCH3)]m precursor. Furthermore, enhanced photocatalytic efficiency of the films is demonstrated by degradation of methylene blue dye.

EFFECT OF ANNEALING TEMPERATURE ON OPTICAL PROPERTIES OF TITANIUM DIOXIDE THIN FILMS PREPARED BY SOL-GEL METHOD

2012 ◽  
Vol 06 ◽  
pp. 13-18 ◽  
Author(s):  
M. T. SARODE ◽  
P. N. SHELKE ◽  
S. D. GUNJAL ◽  
Y. B. KHOLLAM ◽  
M. G. TAKWALE ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Band Gap ◽  
Annealing Temperature ◽  
Optical Measurement ◽  
Sol Gel ◽  
Fesem Image ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystallite Sizes

TiO 2 thin films were deposited on glass substrates by sol-gel method. Nanocrystalline TiO 2 thin films were prepared at ambient conditions and titanium tetraisopropoxide [ C 12 H 28 O 4 Ti ] was used as a Ti -precursor. The effect of annealing temperature on optical properties of nanocrystalline TiO 2 thin films was studied. The as-deposited films were dried at 100 °C for 1 hr. The films formed were further heated in temperature between 200 and 500 °C for 1 hr. The films were characterized by different techniques: XRD, UV-visible spectroscopy, FTIR spectroscopy and FESEM. The characterization studies revealed that the films are crystallized as anatase phase and nano-structured with better optical properties α = 0.89 as compared to reported data. The optical measurement showed the indirect band gap between 3.31 and 3.35 eV with corresponding crystallite sizes between 8.9 and 3.7 nm. The FESEM image of film annealed at 400 °C showed spherical nanocrystalline structure of TiO 2 particles. The crystallite sizes obtained from FESEM image are found to be between 30 and 100 nm. It is also observed that refractive index of the film increases with increasing the annealing temperature. The smaller crystallite size gives larger band gap due to quantum size effects.

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