Improvement of characteristics of Ga-doped ZnO grown by pulsed laser deposition using plasma-enhanced oxygen radicals

The authors report on the growth and characterization of Ga-doped ZnO films grown at a low temperature (100 degrees C) by oxygen plasma-enhanced pulsed laser deposition (PE-PLD). The introduction of oxygen radicals during PLD growth remarkably improved the crystalline quality, surface morphology, and density of Ga-doped ZnO films. The PE-PLD grown Ga-doped ZnO film showed a maximum electron mobility of 46.2 cm(2)/V s and a minimum resistivity of 3.5x10(-4) Omega cm at a radio-frequency input power of 100 W. Average visible (500-700 nm) transparency was improved from 83.7% in the Ga-doped ZnO grown without oxygen radicals to 93.1% in the samples grown with oxygen radicals. The use of oxygen radicals also increased the near-IR (800-3000 nm) transparency. The figure of merit of the Ga-doped ZnO film grown at a radio frequency input power of 100 W showed a maximum value of similar to 0.12 Omega(-1) at wavelengths of 580 nm in the visible range and 1100 nm in the near-IR range. (C) 2008 The Electrochemical Society.