Study of ZnO thin film on silicon substrate by sol-gel spin coating method for bio-medical application

Transparent semiconductor ZnO thin films deposited on p-Si (100) substrates with different solvent (Methanol and Ethanol) were obtained by sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. The influence of surface morphologies, surface roughness, I-V characteristic, crystallization and optical properties with different solvent was investigated. The structural properties of the annealed ZnO films were examined with AFM and XRD. UV-Vis was employed to study the optical properties of the ZnO thin films and the electrical characteristics were obtained by I-V curve tracer. XRD result shows that all polycrystalline ZnO thin film after annealing have the orientation along the (002) plane. The ZnO thin film deposited with methanol solvent provide better transmittance if compared to the ethanol solvent. The deposited ZnO thin film will further use for bio-molecular detection with the idea of immobilization and hybridization of the DNA on the ZnO thin film.