Fabrication and characterization of indium-doped p-type SnO2 thin films

p-Type transparent SnO2 thin films were successfully fabricated by sol-gel dip-coating method using indium as acceptor dopant. The prepared films were characterized by X-ray diffraction, Hall effect measurement, and UV-visible absorption. It was found from the XRD results that all the films with In/Snless than or equal to0.4 were rutile-type structure. Hall effect measurement showed that the conduction type was dependent on the process temperature. For In/Snless than or equal to0.2 and the process temperature above 450degreesC, the films were p-type, while for the process temperatureless than or equal to450degreesC, the films were n-type. It was found that 525degreesC was the optimum processing temperature to obtain p-type SnO2 with highest hole concentration. For In/Sn around 0.3, process temperature was very critical to the conducting type, and for n/Sngreater than or equal to0.4, the film was n-type conducting. (C) 2003 Elsevier B.V. All rights reserved.