AL-DOPED ZNO THIN FILM HUMIDITY SENSOR

摘要

PURPOSE: An Al-doped ZnO thin film humidity sensor is provided to produce a high performance humidity sensor at a low cost by using a compound coating liquid applied through spin coating and thermal treatment. CONSTITUTION: A ZnO coating liquid doped with 0.6wt% of Al is coated on an alumina substrate coated with a silver electrode by spin coating three to five times. After coating, thermal treatment is performed at 300deg.C for 10 minutes. After final coating, annealing is performed at 500-700deg.C for an hour. A humidity sensor is formed of a porous film having nano-sized particles. The thickness of the thin film is less than 235nm, and the particle size of the oxide semiconductor is less than 20.5nm.