Fabrication and Properties of Pulsed Laser Deposited Wide Band-gap Zn0.9Mg0.1O:Ga Conducting Films

Abstract

Wide band gap and highly transparent conductive Ga-doped Zn0.9Mg0.1O (ZMO:Ga) thin films were deposited on glass substrates by pulsed laser deposition (PLD) technique. The properties of the films were characterized through hall effect, double beam spectrophotometer, atomic force microscope (AFM) and X-ray diffraction (XRD). The effects of substrate temperature and post deposition vacuum annealing on structural, electrical and optical properties of ZMO:Ga thin films were investigated. The experimental results show that the electrical resistivity of the film deposited at 200 ℃ is 8.12×10-4Ω·cm, and can be further decreased to 4.74×10-4Ω·cm with post annealing at 400 ℃ for 2h under 3×10-3Pa. In the meantime, its band gap energy can be increased to 3.90eV from 3.83eV. The annealing process leads to the improvement of (002) orientation, wider band gap, increased carrier concentration and blue shift of absorption edge in the transmission spectra of ZMO:Ga thin films.