NO2 gas sensing properties of chemically grown Al doped ZnO nanorods

This report highlights nanocrystalline aluminium doped ZnO (Al doped ZnO: AZO) samples deposited on seeded glass substrates using cost-effective reflux method. The doping concentration of ‘Al’ ions varied from 1 to 3 vol percentage (vol%). The deposited AZO samples exhibit wurtzite hexagonal crystal structure and the surface morphological analysis study confirms the formation of nanorods for undoped ZnO and reduction in diameter with the formation of the fine tips for AZO samples. The photoluminescence (PL) study confirms oxygen vacancies and defects in the AZO samples. Moreover, the AZO samples exhibit excellent gas sensing performance towards NO2 gas at an operating temperature of 175 °C. The gas sensitivity of 5 ppm NO2 gas was 85% at 175 °C. This work is promising for the practical approach for the low detection limit at low operating temperature in the field of gas sensor technology.