Sol-gel synthesis of ZnO thin films

Transparent and crackfree thin films of ZnO have been deposited on fused silica, soda glass, silicon wafers and KBr single crystals using the sol-gel technique. A sol has been prepared by reacting zinc acetate and ethylene glycol and dissolving the resultant transparent brittle solid in dry n-propanol. A proton acceptor like triethyl amine was added to assist hydrolysis of zinc acetate. The resulting solution was readily gelled on addition of water. Films were spin cast on polished substrates, gelled in humid air and pyrolysed at 450 degrees C to get polycrystalline ZnO thin films. The films were characterized using X-ray diffraction. scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-Vis absorption spectroscopy.