Solar Energy Materials and Solar Cells, Vol.94, No.3, 406-412, 2010
Investigations on high visible to near infrared transparent and high mobility Mo doped In2O3 thin films prepared by spray pyrolysis technique
High visible to near infrared (NIR) transparent Mo (0-1 at%) doped In2O3 (IMO) thin films with high carrier mobility were deposited on Corning-1737 glass substrates at 400 degrees C by spray pyrolysis experimental technique. The films were annealed in vacuum (similar to 1 x 10(-4) mbar) at 550 degrees C for 45 min. XRD analysis confirmed that indium oxide belongs to cubic bixbyite structure. The preferred growth orientation along (2 2 2) plane for low Mo doping level shifts to (4 0 0) for higher Mo doping levels. Crystallite sizes extracted from the XRD data corroborate the changes in full-width at half-maximum due to the variation in Mo doping. Scanning electron microscopy study illustrates the evolution in surface microstructures as a function of Mo doping. The negative sign of Hall coefficient confirmed n-type conductivity. Films with high mobility of similar to 149 cm(2)/(V s), carrier concentration of similar to 1.0 x 10(20) cm(-3), resistivity of similar to 4.0 x 10(-4) Omega cm and high figure of merit of similar to 1.02 x 10(-2) Omega(-1) were observed for post-annealed films (0.5 at% Mo). The obtained high average transparency of similar to 83% in the wavelength range 400-2500 nm confirms that transmittance is well extended into the NIR region. (C) 2009 Elsevier B.V. All rights reserved.