Abstract

Zinc oxide is a direct, wide bandgap (3.37 eV) semiconductor material with many promising properties for optoelectronics, transparent electronics, spintronic devices and sensor applications. ZnO has numerous attractive characteristics for electronics and optoelectronics devices. The exciton binding energy is ∼60 meV for ZnO, The room temperature electron Hall mobility in single crystal ZnO is ∼200 cm2 V−1. ZnO has a hexagonal wurtzite crystal structure, with lattice parameters a=3.25� and c=5.12 �. ZnO films have been prepared by a variety of deposition techniques. Among the preparation methods of ZnO films, sol-gel is an excellent method. Coating of substrates by the sol-gel method is very useful for modifying properties of substrates with a large or small surface area or providing substrates with new active properties, which are needed for developing optical, electronic and chemical devices. In this study, ZnO films have been deposited by sol-gel dip coating method. The concentrations of ZnAc solution were adjusted as 0.25, 0.35, 0.45 and 0.55 M. Substrate was dipped at withdrawn speed of 6 mm/min. X-ray diffraction (XRD) results were analyzed to understand the effect of sol concentration on the crystalline structure and orientation of the films. The films exhibited (002) preferred orientation. The surface microstructure of films were investigated for using field emission scanning electron microscopy (FESEM). The electrical transport characteristics (hall mobility and electron concentration) were investigated by a Hall measurement system using the Van der Pauw configuration under 0.55 T magnetic field at room temperature