Electrochromic performance of WO3 thin films with solvent-free viscous electrolytes based on polyethylene glycol-titanium oxide nanocomposites

2011 ◽  
Vol 1312 ◽  
Author(s):  
Narcizo Mendoza ◽  
Liliana Hechavarría ◽  
Francisco Paraguay-Delgado ◽  
Hailin Hu

ABSTRACTPolymeric nanocomposites of polyethylene glycol (PEG) with titanium oxide compound, PEG-Ti, have been prepared by sol-gel method from liquid PEG and titanium isopropoxide in acidic medium. Lithium salt (LiX) has been added into PEG-Ti to form PEG-Ti-LiX polymeric electrolytes. Electrochromic devices based on tungsten oxide thin films and PEG-Ti-LiX electrolyte may show excellent optical transmittance transient, however it depends on the type of lithium salt used during the sol-gel process. With LiI, the color change speed of the devices is very fast but they show a yellow color at bleaching state. The use of LiClO4 makes the devices totally transparent in visible region but the optical contrast is small. Possible molecular structure model of these polymeric electrolytes have been analyzed to explain the relation between electrochromic performance of tungsten oxide and electrolyte chemical composition.

2007 ◽  
Vol 111 (50) ◽  
pp. 18479-18492 ◽  
Author(s):  
Vittorio Luca ◽  
Mark G. Blackford ◽  
Kim S. Finnie ◽  
Peter J. Evans ◽  
Michael James ◽  
...  

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.


2009 ◽  
Vol 25 (02) ◽  
pp. 267-272
Author(s):  
YUAN Jia-Guo ◽  
◽  
ZHANG Yu-Zhi ◽  
LE Jun ◽  
SONG Li-Xin ◽  
...  

2021 ◽  
Vol 24 (3) ◽  
pp. 38-42
Author(s):  
Marwa Mudfer Alqaisi ◽  
◽  
Alla J. Ghazai ◽  

In this work, pure Zinc oxide and tin doped Zinc oxide thin films nanoparticles with various volume concentrations of 2, 4, 6, and 8V/V% were prepared by using the sol-gel method. The optical properties were investigated by using UV-Visible spectroscope, and the value exhibits the direct allowed transition. The average of transmittance was around ~(17-23) %in visible region. The optical energy band gap was calculated with wavelength (300-900) nm for pure ZnO and Sn doped ZnO thin films which decreases with increasing concentration from 3.4 eV to 3.1 eV respectively and red shift. The real dielectric(εr) and the imaginary dielectric εiare the same behavior of the refractive index(n) the extinction coefficient (k) respectively. The optical limiting properties were studied by using an SDL laser with a wavelength of 235 nm. ZnO and doping thin films an found efficient as optic limiting and depend on the concentration of the all samples.


2005 ◽  
Vol 900 ◽  
Author(s):  
A. Deptuła ◽  
Kenneth C Goretta ◽  
Tadeusz Olczak ◽  
Wieslawa Lada ◽  
Andrzej G. Chmielewski ◽  
...  

ABSTRACTTitanium oxide and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl4 and HNO3. The main preparation steps for the sols consisted of elimination of chloride anions by distillation with nitric acid and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to (1) prepare irregularly shaped powders by evaporation; (2) produce by a dipping technique thin films on glass, Ag, or Ti substrates; and (3) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid to the sols.


2019 ◽  
Vol 14 (11) ◽  
pp. 1582-1588 ◽  
Author(s):  
M. I. Khan ◽  
Shahnawaz ◽  
Shahid Imran ◽  
Muhammad Waqas Yousaf ◽  
A. Wahab ◽  
...  

The phases of TiO2 have an important role in the efficiency of dye sensitized solar cells (DSSCs). In this research, the effects of anatase and mixed phases (brookite and anatase) of TiO2 on the efficiency of DSSCs have been reported. 2% Cu doped TiO2 (Cu:TiO2) thin films are prepared by sol–gel dip coating technique. These films are annealed at the temperatures of "350 °C, 450 °C, 550 °C and 650 °C." XRD showed that at 550 °C and 650 °C, films have mixed phases of TiO2. Also, it showed that grain size is increased by increasing temperature. No extra phases of Cu like CuO etc. were observed in XRD graphs, which confirmed that Cu is completely dissolved into TiO2. UV-Vis results showed that all the films have more than 80% transmittance in the visible region. The optical band gap energy (Eg) of films at "350 °C, 450 °C, 550 °C and 650 °C" is 3.96, 3.81, 3.75 and 3.64 eV, respectively. The electrical resistivity of these thin films by four point probe technique is calculated as 121.8 × 102 Ω-m, 95.69 × 102 Ω-m, 86.65 × 102 Ω-m and 76.3 × 102Ω-m respectively. Solar simulator results showed that the current density (Jsc) of mixed phase is higher than single phase, causing higher efficiency. The maximum Jsc 5.12 mAcm–2 is achieved at 650 °C (mixed phase), resulting in higher efficiency of 2.35% which is more than 100 times the efficiency of anatase phase which has 1.18%. This work will provide a way to enhance the efficiency of DSSCs by using mixed phases of TiO2. In future, if 1-D structure of these mixed phases is used in DSSCs then efficiency of DSSCs will improve definitely (or positively).


2013 ◽  
Vol 802 ◽  
pp. 124-128 ◽  
Author(s):  
Krisana Chongsri ◽  
Siriwattana Aunpang ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa

In this work, we report the preparation of Cu-doped ZnOthin films by sol-gel method based on zinc acetate dihydrate (CH3COO)2Zn·2H2O, Copper acetate dihydrate Cu3(CH3COO)2·H2O) and diethanolamine (HN(CH2OH)2, DEA). The precursor solution was prepared at various Cu composition ranging from 2-20 wt%. All films were spin-coated on borosilicate substrates for several coating repetition followed by annealing process at 550 °C for 4 h in an ambient air. The structural properties of the films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD results indicate the domination of hexagonal wurtzite structure of ZnO with noticeable alternation in the XRD peak intensity upon Cu doping content. SEM results revealed the grain size shape and surface morphologies of as-prepared samples. Crucial optical properties of as-prepared films were scrutinized from their UV-Vis transmission spectra. The films are highly transparent in the visible region with more than 90 % transparency within 380 nm to 800 nm. Their corresponding band gaps indicate significant red shift with increasing Cu doping content. Overall results suggest that Cu additive play a vital role on relevant optical properties of ZnO that can be adjusted to meet the requirement for practical optoelectronics applications.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
D. S. C. Halin ◽  
I. A. Talib ◽  
A. R. Daud ◽  
M. A. A. Hamid

Cuprous oxide (Cu2O) thin films were deposited onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives, namely, polyethylene glycol and ethylene glycol. It was found that the organic additives added had a significant influence on the formation of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs, the grain size of film prepared using polyethylene glycol additive has smaller grains of about 83 nm with irregular shapes. The highest optical absorbance film was obtained by the addition of polyethylene glycol. The Cu2O thin films were used as a working electrode in the application of photoelectrochemical solar cell (PESC).


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