scholarly journals Effect of Aging Time and Film Thickness on the Photoelectrochemical Properties of TiO2Sol-Gel Photoanodes

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
D. Regonini ◽  
A. K. Alves ◽  
F. A. Berutti ◽  
F. Clemens
Keyword(s):  
Film Thickness ◽  
Aging Time ◽  
Sol Gel ◽  
Photocurrent Density ◽  
Photoelectrochemical Properties ◽  
Solar Water Splitting ◽  
Electron Collection ◽  
Significant Difference ◽  
Sol Gel Process ◽  
Sol Gel Films

This work has focused on the investigation of a non-aqueous based sol-gel process to produce TiO2based photoelectrodes for solar water splitting. In particular, the effect of the aging time of the sol and TiO2film thickness on the photoelectrochemical properties of the photoanodes has been investigated. In order to achieve optimal performances (i.e., photocurrent density up to 570 µA/cm2and IPCE of 26% at 300 nm), the sol needs to be aged for 3 to 6 h, before being dip-coated to produce the photoanodes. The importance of the aging time can also be appreciated from the optical properties of the TiO2films; the absorbance threshold of the sol-gel aged for 3–6 h is slightly shifted towards longer wavelenghts in comparison to 0 h aging. Aging is necessary to build up a well-interconnected sol-gel network which finally leads to a photoelectrode with optimized light absorption and electron collection properties. This is also confirmed by the higher IPCE signal of aged photoelectrodes, especially below 340 nm. Among thicknesses considered, there is no apparent significant difference in the photoresponse (photocurrent density and IPCE) of the TiO2sol-gel films.

THE EFFECT OF COMPOSITION CHANGE IN SOL-GEL SYNTHESIZED PSC

2008 ◽  
Vol 20 (01) ◽  
pp. 53-59
Author(s):  
Wen-Hsi Wang ◽  
Yuan-Ling Lee ◽  
Chun-Pin Lin ◽  
Feng-Huei Lin
Keyword(s):  
Setting Time ◽  
Sol Gel ◽  
Hydration Product ◽  
Xrd Pattern ◽  
Ph Variation ◽  
Initial Strength ◽  
Filling Materials ◽  
Retrograde Filling ◽  
Significant Difference ◽  
Sol Gel Process

Modified calcium silicate cement had previously been developed as a dental retrograde filling. It had great sealing ability, good biocompatibility, and anti-bacterial properties. However, its clinical application was limited by a long setting time and poor handling property. In previous study,1, 2 the setting property of PSC was greatly improved due the sol-gel process, without the addition of transition metal element. In this study, different ratio of starting material of PSC was prepared. The composition of each group was also altered with the ratio of the starting materials according to the result of XRD pattern. There is no significant difference in pH variation profile between each group. Even though low C 3 S / C 4 AF ratio (DX631 and DX541 groups) possessed high initial strength at first 24 hours after hydration, there was no increase in strength ever since according to the result of microhardness. However, the groups with high C 3 S / C 4 AF ratio (DX811 and DX721 groups) possessed relatively low initial strength at 24 hours after hydration, but the strength increased rapidly and continuously at least for the next six days of hydration. Moreover, the peak intensity of hydration product (Portlandite) on XRD pattern in DX811 group was much higher than other three groups, and this was also in agreement with the result of microhardness. DX811 group is determined to be the optimal one for the further development in the application as root-end filling materials.

scholarly journals Effects of Growth Temperature on the Physicochemical and Photoelectrochemical Properties of a Modified Chemical Bath Deposited Fe2O3 Photoelectrode

2020 ◽  
Vol 58 (4) ◽  
pp. 263-271
Author(s):  
Yaejin Hong ◽  
Seung-Hwan Jeon ◽  
Hyukhyun Ryu ◽  
Won-Jae Lee
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Growth Temperature ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Saturated Calomel Electrode ◽  
Precursor Solution ◽  
Photocurrent Density ◽  
Flat Band ◽  
Photoelectrochemical Properties

In this study, Fe2O3 photoelectrode thin films were grown on fluorine-doped tin oxide substrates at various temperatures ranging from 145 to 220 oC using modified chemical bath deposition. The morphological, structural, electrical, and photoelectrochemical properties of the resulting Fe2O3 photoelectrode were analyzed using field emission scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and a three-electrode potentiostat/galvanostat, respectively. Growth temperature and hydrochloric acid etching both affected the growth of the Fe2O3 photoelectrode, with Fe2O3 thin film thickness first increasing and then decreasing as growth temperature increased. The pH value of the precursor solution varied according to growth temperature, which in turn affected film thickness. The highest photocurrent density (0.53 mA/cm2 at 0.5 V vs. saturated calomel electrode) was obtained from the Fe2O3 photoelectrode grown at 190 oC, which yielded the thickest thin film, smallest full width at half maximum and largest grain size for the (104) and (110) plane, and highest flat-band potential value. Based on these findings, the photoelectrochemical properties of Fe2O3 photoelectrodes grown at various temperatures are strongly affected by their morphological, structural, and electrical properties.

Effect of Solvent Used in the Preparation of Aluminum-Doped ZnO as Electron Acceptor Layer on the Characteristic of its Hybrid Solar Cell

2013 ◽  
Vol 737 ◽  
pp. 74-79
Author(s):  
Annisa Aprilia ◽  
Priastuti Wulandari ◽  
Rahmat Hidayat
Keyword(s):  
Solar Cell ◽  
Electron Acceptor ◽  
Crystal Orientation ◽  
Sol Gel ◽  
Photocurrent Density ◽  
Hybrid Solar Cell ◽  
Ion Concentration ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Aluminum Doped Zinc Oxide

Aluminum doped Zinc Oxide (AZO) layer has been employed as electron acceptor in hybrid solar cell based on Poly(3-hexylthiophene) with inverted structure. AZO layers used in this work were prepared by sol-gel process using two different solvents, namely methanol and methoxyethanol. From X-ray diffraction measurements, AZO layer prepared using methanol solvent (AZO-me) indicates the formation of crystallines with the same (002) orientation, whereas AZO layer prepared using methoxyethanol (AZO-mx) indicates the formation of crystallines with (100), (002), and (101) orientations. The nanomorphology of those AZO layer surfaces was also remarkably different, which might be related to differences in crystal orientation. For both solvents, the photocurrent density-voltage (J-V) characteristics were also affected by the Al ion concentration in AZO layer. However, solar cell with AZO-mx shows better performances in comparison to that of AZO-me with the same Al ion concentration. The observation of performance variations in those fabricated solar cells are suggested to be strongly related with the crystal orientation and nanomorphology of AZO layer. These experimental results then suggest that charge carrier dissociation by AZO layer are significantly influenced by the crystal orientation and nanomorphology of AZO layer, which are affected by the solvent used for preparing the AZO layer.

Effect of Film Thickness on Structure and Property of Pb(Zr0.53Ti0.47)O3 Thin Film

2010 ◽  
Vol 150-151 ◽  
pp. 112-117 ◽  
Author(s):  
Min Xian Shi ◽  
Wei Mao ◽  
Yan Qin ◽  
Zhi Xiong Huang ◽  
Dong Yun Guo
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Film Thickness ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Xrd Analysis ◽  
Structure And Property ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Ferroelectric Hysteresis

Pb(Zr0.53Ti0.47)O3 thin films with thickness of 120nm, 190nm, 310nm, 440nm and 630nm were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process through repeating spining process 2 times, 4 times, 6 times, 8 times and 10 times respectively. The structures of PZT films were investigated by SEM and XRD analysis. The ferroelectric hysteresis loops were recorded by Radiant Precision Workstation and dielectric properties were measured using an Agilent HP4294A impedance analyzer. X-ray diffraction indicated that with the film thickness increasing, the diffraction intensity increased. The thickness of PZT film had great effect on ferroelectric and dielectric properties. Conclusively when the film thickness was about 310nm, the PZT thin films possessed better ferroelectric and dielectric properties.

scholarly journals Ag-Functionalized CuWO4/WO3 nanocomposites for solar water splitting

2019 ◽  
Vol 43 (5) ◽  
pp. 2196-2203 ◽  
Author(s):  
R. Salimi ◽  
A. A. Sabbagh Alvani ◽  
B. T. Mei ◽  
N. Naseri ◽  
S. F. Du ◽  
...  
Keyword(s):  
Water Splitting ◽  
Electrophoretic Deposition ◽  
Sol Gel ◽  
Photocurrent Density ◽  
Solar Water ◽  
Solar Water Splitting

A new plasmonic Ag-functionalized CuWO4/WO3 hetero-structured photoanode was successfully prepared via a PVP-assisted sol–gel (PSG) route and electrophoretic deposition which reveals 4 times enhanced photocurrent density compared with pristine WO3.

Effect of heat treatment on formation of sol-gel (Pb, La)TiO3 films for optical application

1997 ◽  
Vol 12 (3) ◽  
pp. 812-818 ◽  
Author(s):  
Junmo Koo ◽  
Sung-Uk Kim ◽  
Dae Sung Yoon ◽  
Kwangsoo No ◽  
Byeong-Soo Bae
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Film Thickness ◽  
Optical Transmission ◽  
Thick Films ◽  
Sol Gel ◽  
Propagation Loss ◽  
Optical Propagation ◽  
Lanthanum Titanate ◽  
Sol Gel Films

Lead lanthanum titanate [(Pb, La)TiO3] sol-gel films have been prepared to investigate the effect of heat treatment on the fabrication of uniform and crack-free thick films by applying different heating schedules. The surface morphology as well as the optical properties such as refractive index, optical transmission, and optical propagation loss of the films was examined, depending on the film thickness. Because the slower and longer heating is enough to remove the organic and nitrate residues and diminish the thermal shock while heating the films, slower and longer heating can produce the uniform and crack-free thick films having higher refractive index as well as lower optical propagation loss. Also, the drying and heating of the films on a hot plate in every coating resulted in the fabrication of thick films having above 8000 Å without any defects and microcracks. This film presented the highest refractive index as well as the lowest optical propagation loss which grows exponentially with increasing the film thickness due to the scattering of defects in the film.

Photoinduced Birefringence in Nanostructured SiO2:DR1 Sol–Gel Films

2008 ◽  
Vol 8 (12) ◽  
pp. 6576-6583
Author(s):  
Alfredo Franco ◽  
Jorge A. García-Macedo ◽  
I. G. Marino ◽  
P. P. Lottici
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Sol Gel ◽  
Sodium Dodecyl ◽  
X Ray Diffraction ◽  
Pump Probe ◽  
Heat Treated ◽  
Sol Gel Process ◽  
Photoinduced Birefringence ◽  
Xrd Patterns ◽  
Sol Gel Films

Pump-probe photoinduced birefringence measurements were carried out in amorphous and in nanostructured sol–gel films with Disperse Red 1 (DR1) azochromophores embedded in a SiO2 matrix. X-ray diffraction (XRD) patterns determine the long-range nanostructure order of the films, exhibiting a lamellar nanostructure, with two different d-spacings, due to the presence during the sol–gel process of the Sodium Dodecyl Sulfate (SDS) or of the Cetyltrimethylammonium Bromide (CTAB) ionic surfactants. The photoinduced birefringence measurements were performed on fresh and on heat treated films as a function of the pumping time. The measurements give us information about the effect of the nanostructures on the azochromophores orientation dynamics. As a result, for the same azochromophores concentration, annealed nanostructured films exhibited the largest azochromophore mobilities but by the other side, amorphous films had the largest signal intensities. Besides, we established a phenomenological model for the analysis of the azochromophores orientation in the films as a function of the pumping time.

Correlation of Thickness with the Photocatalytic Characteristic of TiO2 Thin Films

2005 ◽  
Vol 486-487 ◽  
pp. 65-68 ◽  
Author(s):  
Sang Wook Lee ◽  
Hyun Suk Jung ◽  
Dong Wook Kim ◽  
Kug Sun Hong
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Stearic Acid ◽  
Band Gap ◽  
Uv Light ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Tio2 Films ◽  
Tio2 Thin Films ◽  
Sol Gel Process

5, 10, and 30 nm thickness of transparent TiO2 thin films were fabricated using sol-gel process, and the influence of film thickness on the photocatalytic property was investigated. The increase in film thickness was found to enhance the photocatalytic property of the films. Photocatalytic properties of each film were estimated by decomposition of stearic acid. The amount of decomposed stearic acid increased with film thickness (5 - 30 nm). For the case of 30 nm thickness film, the stearic acid was decomposed perfectly in twelve minutes. UV-vis spectra and photocurrents of each film clearly showed that the photoactivities of TiO2 films were related to the amount of absorbed UV light and band gap shift.

Dielectric and Transverse Piezoelectric Characterization of Sol-Gel Derived Pb(Mg1/3Nb2/3)O3-PbTiO3 (70/30) FILMS WITH {100} and {111} Textures

1999 ◽  
Vol 596 ◽  
Author(s):  
Jeong Hwan Park ◽  
Susan Trolier-McKinstry
Keyword(s):  
Film Thickness ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Silicon Substrates ◽  
Sol Gel Process ◽  
Oriented Films ◽  
Tan Δ ◽  
Passivated Silicon ◽  
Pt Films

AbstractHighly {100} and {111} oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 (70/30) films were deposited on Pt(111)-passivated silicon substrates using a modified sol-gel process. In both cases, the degree of preferred orientation did not change with film thickness from 0.56 μm to 1.5 μm. The room temperature dielectric constants for the {100}-oriented films were 2100–2650, while those for the {111} oriented films were 1900–2350. In both cases tan δ was less than 0.03. It was found that the piezoelectric coefficient (d31) of the PMN-PT films increased with increasing film thickness. The d31 coefficient of highly {100} oriented PMN-PT films poled for 5 minutes at 85 kV/cm were found to range from –45 to –86 pC/N assuming a Young's modulus of 35 GPa. Highly {100} oriented PMN-PT films showed larger piezoelectric coefficients than {111} oriented films. Results on aging of the piezoelectric coefficients for the differently oriented films are also presented.

Comparative Study of Thin PZT Sol-gel Films Deposited on Pt and GaN Substrates

2007 ◽  
Vol 1034 ◽  
Author(s):  
Serguei A. Chevtchenko ◽  
Francisco A. Agra ◽  
Jinqiao Xie ◽  
Hadis Morkoç
Keyword(s):  
Comparative Study ◽  
Remanent Polarization ◽  
Piezoelectric Coefficient ◽  
Sol Gel ◽  
Piezoresponse Force Microscopy ◽  
Force Microscopy ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Pzt Films ◽  
Sol Gel Films

AbstractWe provide a comparative study of the piezoresponse in thin Pb(ZrxTi1−x)O3 (PZT) films deposited onto GaN/sapphire and Pt/Ti/SiO2/Si substrates using the sol-gel process. The effective piezoelectric coefficient was measured by Piezoresponse Force Microscopy. The resulting effective piezoelectric coefficient obtained for PZT(∼180 nm)/GaN/sapphire structure is 16.7 ± 3.4 pm/V and for PZT(∼180 nm)/Pt/Ti/SiO2/Si structure is 7.8 ± 0.8 pm/V. We also discuss the substrate clamping effect of both structures and explain the relatively stronger piezoresponse of PZT on GaN by different orientation of films formed on the two types of substrates. In this investigation, the PZT thin films crystallized with preferred (100) and (110) orientations on platinum and GaN, respectively. The phase mode of the Piezoresponse Force Microscopy was used to demonstrate remanent polarization in PZT/GaN/sapphire structure.

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