Al doped ZnO nanogranular film fabricated by LBL method and its application for gas sensors

The Al doped ZnO nanogranular films were fabricated by layer-by-layer (LBL) self-assembly method and the gas sensitivity of ZnO films were investigated. The results show that sensitivity of Al:ZnO gas sensors is up to 12 against 20000 ppm hydrogen, while the response time and recovery time of the sensor are only 8 s and 9 s respectively. The high sensitivity and fast response-recovery time are attributed to the high surface-to-volume ratio of nanogranular films.