Study on Gas Sensor of Hybrid Organic Molecule and Sensitive Properties of Toxic Gas

Abstract

According to the low power and the chemical modifiction properties of organic gas-sensing material, the organic semiconductor material of molecule hybrid CuPc and PANI was used as gas-sensing film, and the gas sensor which has high selectivity to toxic gas was investigated. CuPc was synthesized with Phthalonitrile and p-Cresol as the source material of benzene ring by the template synthesis method of two steps reaction. Through doping with perchloric acid, vitriol and nitric acid, semiconducting doped PANI was obtained. By means of molecular hybrid modification, the intermediate substance of CuPc and PANI was polymerized and formed a kind of new organic semiconductor material CuPcxPANI1-x. Sensor chip was made by virtue of semiconductor technology; the combination of chip and new sensitive material was achieved by virtue of vacuum coating technology. The film surface morphology were characterized through SEM, and it showed that the sensitive material was made of rounded particles whose diameter was about 200nm; the surface of film was deposited by odontoid particals, whose diameter is 200nm or so, and relatively uniform, and its aperture is ordered. The gas sensing properties of thin film were tested by static volumetric method. The results indicate that the new organic semiconductor hybrid material is sensitive to the toxic gases of sulfur dioxide, nitride dioxide, chlorine ect.; the selectivity can be improved by changing the ratio of the distribution; When the heating voltage is 1.5V, the output resistance can be stabilized within 5% and the sensitivity within 10% in 6 months.