The electrical characteristic of nanostructured zinc oxide thin films for ammonia sensor applications / Siti Asiah Kamaruddin

The nanostructured Zinc Oxide (ZnO) thin films have been synthesized using sol-gel method. The ZnO thin films have been deposited on the glass substrate by using the spin coating technique. The ZnO thin films were annealed at 500°C temperature for five different annealing times. The Field Emission Scanning Electron Microscopy (FESEM) and Scanning Electron Microscopy (SEM) were used to examine the surface morphology and particle of the deposited ZnO thin films. The thin films electrical characteristics were investigated using the current - voltage (I-V) measurement to analyze the conductivity and resistivity behaviour of the thin films. The ZnO based ammonia (NH3) sensors have been fabricated and characterized. The electrical characteristics of the thin films show that the conductivity increases with longer annealing time. The sensor responses towards ammonia gaseous were investigated through homemade NH3 sensing characteristic measurement system. The NH3 gas sensing characteristics show that the current responses and sensitivity increase with longer annealing time.