Gasochromic and electrical properties of Pt-nanoparticle-dispersed tungsten oxide thin films prepared by a sol-gel process

2012 ◽  
Vol 1400 ◽  
Author(s):  
Yuki Yamaguchi ◽  
Keishi Nishio ◽  
Tohru Kineri
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Optical And Electrical Properties ◽  
Pt Nanoparticle ◽  
Gas Concentration ◽  
Sol Gel Process ◽  
The Relationship

ABSTRACTIt is well known that tungsten tri-oxide (WO3) exhibits electrochromic and gasochromic properties. When Pt-nanoparticle-dispersed tungsten oxide (Pt-WO3) is exposed to hydrogen gas, the optical and electrical properties of the Pt-WO3 change drastically. Consequently, it is expected that thin films of WO3 can be applied as hydrogen gas leakage sensors. In this study, thin films of Pt-WO3 were prepared on glass substrates using a sol-gel process. The optical and electrical properties of the films were evaluated. Amorphous and crystalline WO3 were easily obtained by changing the heat-treatment temperature. The ion diffusion coefficient of the film depended on the WO3 structure (i.e., whether it was amorphous or crystalline) because the density of amorphous WO3 is lower than that of crystalline WO3. Films with low crystallinity were found to have superior chromic properties to both those with high crystallinity and amorphous films. Thin films of Pt-WO3 prepared at 673K showed the largest change in optical transmittance and electrical conductivity when exposed to H2 gas compared with thin films prepared at other temperatures. When this film was exposed to 100% H2 gas, the normalized transmittance decreased rapidly (in less than 0.2 sec) from 100% to almost 50%. The optical absorbance of the film was dependent on the H2 gas concentration (mixed with N2 gas) in the range from 0.1 to 5% and the relationship between them was linear. The relationship between the electrical conductivity and hydrogen gas concentration (mixed with N2 gas) in the range from 100 to 10000ppm was also linear.

Investigation of Electrical Hydrogen Detection Properties of Pt/WO3 Thin Films Prepared by Sol-Gel Method

2011 ◽  
Vol 485 ◽  
pp. 271-274 ◽  
Author(s):  
Yuki Yamaguchi ◽  
Tohru Kineri ◽  
Masakatsu Fujimoto ◽  
Hideo Mae ◽  
Atsuo Yasumori ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Tungsten Trioxide ◽  
Sol Gel ◽  
Optical And Electrical Properties ◽  
Pt Nanoparticle ◽  
Gas Concentration ◽  
Gas Atmosphere ◽  
Sol Gel Process ◽  
Sensor Devices

Platinum (Pt)nanoparticle-dispersed tungsten trioxide (WO3) thin film is a gasochromic material that changes color from transparent to blue in an H2 gas atmosphere. The electrical conductivity of Pt-nanoparticle-dispersed WO3 is dependent on inserted protons and electrons, though the material is insulator in air, because these electrons and protons work as electrical carriers in WO3. In this study, Pt-nanoparticle-dispersed WO3 thin films were prepared using the sol-gel process, and the optical and electrical properties were evaluated in an atmosphere with or without H2 gas. Pt/WO3 thin films prepared at 400°C showed the largest change in electrical conductivity when exposed to 1% H2 gas compared with thin films prepared at other temperatures. The electrical conductivity of the film was dependent on an H2 gas concentration in the range from 100 ppm to 1%. Pt/WO3 thin films prepared by the sol-gel process are expected to be used for H2 gas sensor devices due to the linear relationship between the electrical conductivity and H2 gas concentration.

Structural, Optical and Electrical Properties of Titanium Dioxide Thin Films with Different Molarity

2013 ◽  
Vol 667 ◽  
pp. 58-62 ◽  
Author(s):  
S.K.M. Maarof ◽  
Saifollah Abdullah ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Electrical Properties ◽  
Sol Gel ◽  
Visible Region ◽  
Optical And Electrical Properties ◽  
A Value ◽  
Sol Gel Process ◽  
Coating Method ◽  
Titanium Dioxide Thin Films

Titanium dioxide, TiO2 is one of the semiconductor materials that can be produced in many ways, such as magnetron sputtering, CVD, and sol-gel process. This paper studied on the production of TiO2 by sol-gel method using titanium tetra (IV) isopropoxide, TTiP. The solution of TiO2 then deposited as a thin films onto glass substrate by spin-coating method. The purpose of this paper is to investigate the effect of molarity on the morphology, optical and electrical properties of the thin films. The effect on the morphology was observed by AFM. The electrical properties then observed by IV characteristic and finally on the optical properties were investigated by UV-Vis. The transmission obtained from UV-Vis showed that TiO2 thin films are decreased around 18% at higher molarity in a visible region. The bandgap also decrease at high molarity. Higher molarity of TiO2 in current-voltage characteristic gave a value of current density for 1.03×10-4 A/m2 and resistivity 1.95×107 Ωm.

Effect of Gamma Radiation on Structural, Optical and Electrical Properties of nanostructured CdHgTe Thin Films

2018 ◽  
Vol 1 (1) ◽  
pp. 26-31 ◽  
Author(s):  
B Babu ◽  
K Mohanraj ◽  
S Chandrasekar ◽  
N Senthil Kumar ◽  
B Mohanbabu
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Gamma Radiation ◽  
Glass Substrate ◽  
Gamma Ray ◽  
Optical And Electrical Properties ◽  
Deposition Technique ◽  
Polycrystalline Structure ◽  
Dc Electrical Conductivity

CdHgTe thin films were grown onto glass substrate via the Chemical bath deposition technique. XRD results indicate that a CdHgTe formed with a cubic polycrystalline structure. The crystallinity of CdHgTe thin films is gradually deteriorate with increasing the gamma irradiation. EDS spectrums confirms the presence of Cd, Hg and Te elements. DC electrical conductivity results depicted the conductivity of CdHgTe increase with increasing a gamma ray dosage

Microstructural, Optical and Electrical Properties of ZnO:Sn Thin Films Deposited by Sol-Gel Method

2013 ◽  
Vol 652-654 ◽  
pp. 519-522
Author(s):  
Jun Chen ◽  
Yue Hui Hu ◽  
Hong Hao Hu ◽  
Yi Chuan Chen
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Sol Gel ◽  
Hexagonal Structure ◽  
Optical And Electrical Properties ◽  
Axis Orientation ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sn Doping ◽  
Glass Substrates

Transparent thin films of Sn-doped ZnO (ZnO:Sn) were deposited onto silica glass substrates by the sol–gel method. The effect of different Sn doping on the crystallinity, structural, optical and electrical properties of ZnO:Sn thin films were investigated by XRD, SEM, UV-VIS spectrophotometer and four-point probe method respectively. Among all of ZnO:Sn thin films in this paper, Sn-doped with 2 at.% exhibited the best properties, the surface demonstrate an accumulative crystallization and hexagonal structure, with a high-preferential c-axis orientation, namely an average transmittance of 90% and the resistivity of 19.6 Ω·cm.

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