Gas Sensors Based on Drop-Casted ZnO Nanowires and Micro-Cantilever Printed Ag Contacts

In this work, we report the usage of micro-cantilever printed silver nanoparticles (AgNP) contact pads for fabrication of ZnO nanowire (NW) Schottky diode-based sensors for detecting CO₂, CO and NO₂ in ppb range at room temperature. The fabrication process is divided in two phases. In first phase, a ZnO NW mat based sensor is developed by simple drop-casting techniques to first confirm the response of ZnO NWs to the pollutant gases. In the second phase, the sensor is optimised with the help of micro-cantilever printing technique by reducing the channel gap between the AgNP pads and forming a ZnO NW bridge having less density of NWs and a higher surface-to-volume ratio. The goal is to develop a low-cost and simple process for rapid sensing of air pollutants at room temperature.