Fabrication of Zinc Oxide nanoflakes nitrogen sensor / Siti Aishsah Lewon

In this study, sol-gel immersion method using Urea as stabilizer was proposed in order to fabricating Zinc Oxide nanoflake on gold-seeded Silicon substrate. The immersion time of samples was differentiate at at 12 hour, 24 hours, 36 hours and 48 hours.The ZnO nanoflake arrays formed on the substrate were characterized using field emission scanning electron microscope (FESEM) and Photoluminescence (PL) spectrum. Among 4 samples, Zn036IT sample has good adhesion of morphology surface was detected. It expected to be a good sensor. The ZnO nanoflake then was used to produce Nitrogen, N2 sensor base on their ability of good electrical and optical properties. The N2 was chosen because it presence colorless, odorless at environment that can effect to humans and ecosystems. From PL spectrum analysis, the energy gap of ZnO nanaflake is fewer than bulk ZnO. The ZnO nanoflake has higher conductivity compared to bulk ZnO. Actually, the rate of concentration of N2 flow inside container is consistent at 5.0 bubbles /second and means that the sensor is sensitive toward the rate of N2 at 5 bubbles/ second. The sensitivity of a sensor can be measure using l-V testing. From the result, the higher sensitivity sensor is Zn036IT sample with 90% sensitivity. Compared to others, their sensitivity is 87 % and 81% for samples Zn048IT, Zn012IT and Zn024IT. Since the Zn036IT sample has good adhesion of morphology surface, Eg of 3.1 eV, highest resistivity and sensitivity, it's enough to support it as a good sensor. Base on l-V testing graph, it has low voltage to sense a low concentration of N2 flow inside container. In result, it has low power consumption.