Bandgap Modulation in ZnO Through Doping By Sol-Gel Method

Abstract

Zinc oxide is a promising optical material for possible application in solid state lighting. Highly transparent and nanocrystalline Zinc Oxide thin films with different concentration of Cadmium and Magnesium are deposited on corning 7059 glass by sol-gel spin coating method. The transparent and homogeneous sol of 0.2 mol/l concentration is prepared by dissolving zinc acetate dihydrate in 2-methoxyethanol. Monoethanolamine is used as sol stabilizer. The calculated amounts of cadmium acetate dihydrarte and magnesium acetate tetrahydrarte are added for doping. All the samples are annealed at 550 °C in air ambient for an hour. The doping is confirmed by X-ray diffraction and the bandgap is measured by UV-Vis spectroscopy. The bandgap successfully modulated from near ultraviolet region (3.29 eV) to far ultraviolet region (3.83 eV).