Highly-sensitive NO2 Detection of ZnO Nanorods Grown by a Sonochemical Process

Solution-based growth is utilized to grow ZnO nanorods at room temperature in a very efficient and cost-saving way to make a thin-film device. We fabricated a NO2-gas-sensitive ZnO-nanorod (NR) device by spin-coating a solution containing ZnO NRs on a patterned substrate and obtained good electrical properties having Ohmic contact between the ZnO NR, sensing layer and the metal electrodes. We also studied the gas-sensing property of ZnO-NR-based sensor under N-2 and dry air condition and confirmed that our sensor showed a very high sensitivity to NO2 gas with concentrations much below the sub-ppm level.