Fabrication of zinc oxide thin films using solution immersion method / Amir Hafiz Khairudin

Zinc oxide (ZnO) nanoparticles were successfully synthesized by solution immersion method. The zinc nitrate hexahydrate was use as a precursor, hexamethylenetetramine as a stabilizer and gold seeded was used as a function of catalyser. The zinc oxide thin films obtained were annealed at different temperatures (350°C, 400°C, 450°C and 500°C). The effect of annealing temperature on the crystal structure, optical and electrical properties of the ZnO nanoparticles were characterized using X-ray diffraction (XRD), UV-Vis spectrometry, photoluminescence spectrometry and I-V measurement. XRD results showed that all the peaks obtained were corresponding to the hexagonal wurtzite structure. Photoluminescence spectrometry showed two peaks which is high intensity at wavelength of range 375 nm - 425 nm and higher at 450 nm - 800 nm and this indicates clearly two emission bands corresponding to the band edge emission and defects related emission respectively. UV-Vis spectrometry graph obviously showed high absorbance at wavelength 280 nm - 350 nm which means that all the films are highly absorbance at ultraviolet region. Meanwhile, I-V measurement exhibits the highest slope at 500°C and then followed room temperature (RT), 350°C, 450°C and 400°C. The current at a given voltage for the films at 500°C higher than other annealed temperature. This indicates that the annealing temperature at 500°C increases the production of electron-hole pairs.