Comparative NO2 gas-sensing performance of the self-heated individual, multiple and networked SnO2 nanowire sensors fabricated by a simple process

Gas nanosensors with good “3S” (sensitivity, selectivity and stability), ultralow power consumption and low cost are increasingly needed for portable electronic devices. Herein, we demonstrate the facile fabrication process of individual, multiple, and networked SnO2 nanowire (NW) sensors, which can be used to detect highly toxic NO2 gas based on the Joule self-heating effect, consuming only few tens of μW of power. Systematic investigation on the gas-sensing properties reveals that the individual NW sensor shows advantages, such as better gas response shorter response-recovery time and lower power consumption over multiple and networked NW sensors. The self-heated individual NW sensor with applying a bias voltage of 25 V exhibits a good response to NO2 gas concentrations as low as 1 ppm with short response (∼8 s) and recovery times (∼25 s) and consumes only 35 μW of power. In addition, the gas-response of individual NW sensors operated by either self- or external heating was compared to demonstrate the advantages of the development of the sensor concept for practical applications.