Energy, Vol.39, No.1, 6-10, 2012
Electric properties and surface structure of TiO2 for solar cells
In this paper the electric properties of Titanium dioxide (TiO2) thin film, which is one of most basic functional materials, were studied for the purpose of solar cell applications. As an initial step, it describes the preparation of thin films of TiO2 by the sol-gel dip-coating technique on ITO conducting glass substrates. It then discusses the fabrication of the Al/TiO2/ITO device and the characterization of direct current (DC) electrical properties of TiO2 thin films. The current voltage I (V) properties of TiO2 were measured under different temperatures from 80 to 400 K, using a digital Keithley 6571A electrometer. The I (V) characteristics appeared to be ohmic at low voltage and the space charge was limited (SCL) at higher voltage. The activation energy (E-a) of TiO2 was also calculated to yield two values, depending on the temperature regime. As the particle increased in size, the conductivity increased while the grain boundary effect was reduced. The results show that the film was the conductor. The surface structure of TiO2 was studied to reveal the film's uniformity and nanoparticles. (c) 2011 Published by Elsevier Ltd.