Characterization of ZnO thin film deposited by sol-gel process

Abstract

ZnO is a wide band gap semiconductor which is used as transparent electrode in solar cells, chemical and gas sensors and light emitting diode etc. This paper reports the sol gel preparation and characterization of ZnO thin film. ZnO thin film was prepared by sol-gel process using zinc acetate dehydrate as a precursor, 2-methoxy ethanol as a solvent and monoethanolamine (MEA) as a stabilizer. The solution was deposited on n-type silicon (111) substrate by spin coating at 3000 rpm. Hydrolysis and condensation process produced a complex solution. After drying at 300°C, samples were annealed at 575°C in nitrogen ambient. Precise control of concentration of precursor, solvent used, spinning speed of the substrate and heat treatment conditions, are the factors which strongly affect the crystallographic orientation and morphology of the resultant ZnO films. The crystalinity of the film as found from X-ray diffraction (XRD) had different orientations, with (002) orientation as most intense having a grain size of 44 nm. © 2010 American Institute of Physics.