Highly conductive and transparent Al-doped ZnO films on glass substrate via incorporating hydrogen at low substrate temperatures

Al-doped ZnO (AZO) transparent conducting films were prepared on glass substrates by RF magnetron sputtering at substrate temperatures of 100 degrees C and 250 degrees C with various hydrogen contents in sputtering ambient. The effects of substrate temperature on the effectiveness of hydrogen incorporation in Al-doped ZnO films were compared and investigated. The microstructural, electrical and optical properties of AZO films were systematically analyzed by surface profiler, X-ray diffractometry, scanning electron microscope, four-point probe measurement and UV/vis spectrophotometer. The results indicate that hydrogen is incorporated at low substrate temperature is more effective in improving crystallinity and electrical properties of AZO films than at high substrate temperature. The lowest resistivity of 6.0 x 10(-4) Omega.cm and the average transmittance of more than 85% in the visible range were obtained with hydrogen incorporation at substrate temperature 100 degrees C. (C) 2012 Elsevier B.V. All rights reserved.