산화물 반도체형 후막 가스센서의 이산화질소 감지 특성 = NO2 Sensing Properties of Oxide Semiconductor Thick Films

다국어 초록 (Multilingual Abstract)

The thick films of oxide semiconductors such as WO₃, SnO₂ and ZnO for the NO₂ detection of sub-ppm range have been prepared and their characteristics were investigated. It is showed that the optimum operating temperatures of the sensors are 300℃ and 220∼260℃ for WO₃-based and SnO₂-based thick films, and ZnO-based thick films, respectively. Since the resistance of ZnO-based thick films are extremely high($gt;l0^6Ω), the signal to noise ratio was comparatively low. In order to determine the selectivity, the films are exposed to the interfering gases such as ozone, ammonia, methane and the mixture of carbon monoxide and propane. WO₃-ZnO(3 wt.%) and SnO₂-WO₃(3 wt.%) thick film sensors show high sensitivity, good selectivity, excellent reproducibility and the linearity of NO₂ concentration versus sensor resistance. The preliminary results clearly demonstrated that the sensor can be successfully applied for the detection of NO₂ in sub-ppm range.