The Zn (NO3)2.4H2O (zinc nitrate tetrahydrate) and
Al (NO3)2.9H2O (aluminum nitrate nonahydrate) (Merck) are used as a precursor. ZnO precursor solution with the concentration of 0.15 M was made by dissolving 0.89 grams of powder precursor Zn(NO3)3.4H2O in 40 ml of solvent. Solvent comprises a mixture of 30 ml deionized water and 10 ml of ethanol. To speed up the process of dissolution, the mixture was stirred using a magnetic stirrer for 30 minutes. The next process is to add the certain amount of urea catalyst to accelerate the reaction. Urea was added slowly to a solution of Zn(NO3) 3.4H2 O. Then, the mixture was stirred using magnetic stirrer for 30 minutes. Al dopant obtained from …show more content…
Al dopant in the experiments were made in three variations of the dopant 3% mol, 5% mol and 7% mol Al precursor to
ZnO precursor, respectively. After characterize the composition of Al dopant was 1.48 at%, 2.9 at% and 3.55 at% Al, respectively. The fabrication processes of AZO thin films are similar to the fabrication process of pure ZnO thin film.
Alumina substrate coated by electrodes was immersed in a solution of ZnO and AZO precursors. The temperature is set at 60 °C for 2 days for aging. After that, the samples were cleaned with acetone, and then dried at room temperature for later performed in heat treatment process. In this process, the samples will be dried in the furnace using a temperature of 300 °C for 30 minutes. Finally, the sample is ready to the further characterization and measurement for sensor performance testing