2001 Fiscal Year Final Research Report Summary
Fabrication and practical application of metallo-phthalocyanine thin film-based NO_2 gas sensor
| Project/Area Number |
12650343
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電子デバイス・機器工学
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| Research Institution | Shizuoka University |
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Principal Investigator |
MURAKAM Kenji Shizuoka University, Research Institute of Electronics, Associate Professor, 電子工学研究所, 助教授 (30182091)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Kenzo Shizuoka University, Research Institute of Electronics, Professor, 電子工学研究所, 教授 (70022142)
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| Project Period (FY) |
2000 – 2001
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| Keywords | NO_2 gas sensors / organic thin film / fluoroaluminmu phthalocyanine (AlFPc) / substituted metallo-phthalocyanine / gas response characteristics / vacuum sublimation method / asymmetric side chain / molecular orientation |
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| Research Abstract |
Copper phthalocyanine thin films with the thickness of 200 nm have shown good gas response characteristics in the NO_2 ambience at the operation temperature of 150 ℃, after the HF treatment of glass substrates. However, there are still some problems from the viewpoint of practical uses. Fabrication of very thin film is one of the methods to solve them. Reduction in the thickness of film is expected to lead a faster gas response and improved recovery characteristics. At the same time, reduction in the gas sensitivity may be caused. Fluoroaluminum phthalocyanine (AlFPc) molecules have a linear backbone (Al-F)_x surrounded by a stack of planar Pc rings, which may result in a high conductive very thin film.
The AlFPc films with the thickness of 10 to 20 nm have been deposited on the non-treated glass substrate by using a vacuum sublimation method in the vacuum of 10^<-4> Pa range. The films have revealed an enough electric conductivity for the use of practical gas sensor element as expected
… More
. The gas response characteristics for the cycle of doping and dedoping of 1 ppm NO_2 gas have also showed the high gas sensitivity, the faster response rate and the good recovery characteristics even at the operation temperature of 80 ℃. These results can be interpreted by the specific array of the AlFPc molecules in the film and the decrease in diffusion of NO_2 gas molecules into the film. As a result, the very thin film based on AlFPc molecules is a promising material for the practical application to thin film-based NO_2 gas element.
In order to fabricate a more highly oriented very thin film, substituted AlFPc molecules, fluoroaluminum tetra-t-butyl-phthalocyanine (AlFPc(C_4/H_9)_4) and fluoroaluminum octa-methyl-phthalocyanine (AlFPc(CH_3)_8) have been synthesized. Since both molecules have been substituted by the asymmetric groups, they may cause more specific arrays in the vacuum sublimed thin films. Furthermore, the substituted groups may improve the gas response characteristics due to their electron-donating effect on the AlFPc macrocycles. Indeed, the vacuum sublimed very thin films based on both substituted AlPcF molecules have shown the improved NO_2 gas response characteristics. The results also suggest that the substitution of AlFPc molecules is another approach to realize the practical thin film-based NO_2 gas sensors. Less
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Research Products
(4 results)
