Tailoring Sb doping concentration to achieve p-type nanostructured ZnO thin film grown by sol-gel method

Abstract

Highly c-axis oriented undoped and antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on a glass substrate by the sol-gel spin coating method. Six layers of deposition were repeated with 300 degrees C heat treatment for each layer then samples were annealed at 500 degrees C under an ambient atmosphere. Hall effect measurements revealed that 1%, 2%, and 3% Sb-doped ZnO samples presented p-type conductivity, while the 5% Sb-doped ZnO sample had n-type conductivity. Moreover, the resistivity of the samples was about in the order of 10(3) Ocm. All of the deposited thin films have displayed high transparency, around 90%, implying that they are suitable for optoelectronic applications. Further, the near UV absorption edge moved to the lower wavelength side, causing the bandgap to expand from 3.255 to 3.269 eV. PL spectrum showed that a near band edge UV emission and two broadband peaks detected around 500 nm and 595 nm tend to disappear with Sb doping.