Fabrication of ZnO thin films from nanocrystal inks

Abstract

Zinc oxide nanocrystals were prepared in ethanol and spin-cast to form semiconductor nanocrystal thin films that were thermally annealed at temperatures between 100 and 800 °C. Particle size, monodispersity, and film porosity were determined by X-ray diffraction, ultraviolet-visible absorption spectroscopy, and spectroscopic ellipsometry, respectively. Film porosity rapidly decreased above 400 °C, from 32% to 26%, which coincided with a change in electronic properties. Above 400 °C, the ZnO electron mobility, determined from FET transfer characteristics, increased from 10-3 to 10-1 cm2 V s-1, while the surface resistivity, determined from electrical impedance, decreased from 107 to 10 3 ω m ..