Nitrogen Dioxide Sensing Properties and Mechanism of Copper Phthalocyanine Film

Copper phthalocyanine film, a p-type organic semiconductor, is synthesized by vacuum sublimation and its surface morphology is characterized by SEM. A silicon-based copper phthalocyanine film gas sensor for NO₂ detection is fabricated by MEMS technology. The results show that the resistance and sensitivity of copper phthalocyanine film decrease obviously as the NO₂ concentration increases from 0ppm to 100ppm. However, the sensitivity nearly keeps a constant of 0.158 between 30ppm and 70ppm. The best working temperature of the gas sensor is 90°C for NO₂ gas concentrations of 10ppm, 20ppm and 30ppm, which is much lower than that of general metal oxide gas sensor.