A facile fabrication of semiconductor nanowires gas sensor using PDMS patterning and solution deposition

This paper suggests a simple and cost-effective method for fabricating nanowire (NW) gas sensors. Oxide NWs were deposited uniformly over a defined electrode area by coating with a solution containing NWs after patterning with polydimethylsiloxane (PDMS). The hydrophobic PDMS guide wall prevented outstretching of the deposited solution, which allowed the density of the NWs in the sensor to be manipulated conveniently. The high-density NWs sensor enhanced the gas sensitivity toward CO, C3H8, C2H5OH, and NO2 but reduced the gas response and recovery speed. The correlation between the NW density and gas sensing characteristics are discussed in relation to the gas sensing mechanism.