ИСТИНА

One of the major disadvantages of currently available semiconductor gas sensors are relatively high operating temperature and power consumption, which limits their use in a miniaturized gas analyzers and fire detectors In recent years, several reports on the use of photoactivation to increase gas sensitivity of a metal oxide semiconductor appeared. However, the published studies were conducted using a powerful UV radiation, which does not significantly reduce the power consumption of the semiconductor gas sensor. This work reports the study of photoconductivity and visible light activated room temperature gas sensors properties of semiconductor nanoheterostructures based on wide gap metal oxides and A2B6 quantum dots. Nanocrystalline metal oxides SnO2 and ZnO were synthesized by wet chemical method. CdSe QDs were obtained via high temperature colloidal synthesis. Immobilization of sensitizers on metal oxide surface leads to the increase of room temperature metal oxide conductance in 50 – 104 times, which greatly simplifies the measurement of the sensor signal. Sensor measurements demonstrated that sensitized nanocrystalline semiconductor oxides can be used for CO and NO2 detection under visible light illumination at room temperature without any thermal heating.