Synthesis and Characterization (Electrical and Optical) of TiO2 Doped with MnO2
T. E. Amakoromo
*
Department of Physics/Electronics Technology, School of Science Laboratory Technology, University of Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
TiO2 is vastly used in several industries due to its several properties, its wide bandgap and poor ionic conductivity has however hampered its application in the energy industry. In this work, TiO2 has been doped with MnO2 to produce thin films. The doping was carried out in 5, 10 and 15 wt% of MnO2 and the resultant films characterized (uv/vis photospectroscopy and 4-point probe conductivity test). It was observed that the electrical conductivity was highly improved as was observed in the conductivity test which showed the conductivity of pure TiO2 at 0.0100Ω-1m-1, increase to 0.0217 Ω-1m-1 at 5wt% of MnO2 , and to 0.0409Ω-1m-1 at 10wt% and finally to 0.0749wt Ω-1m-1 at 15wt% of MnO2. The improvement in the conducting properties were also made evident by the drastic reduction in the bandgap energy of TiO2 which reduced for 3.2eV of pure TiO2 to 2.7eV, 2.2eV and 1.7eV for 5wt%, 10wt% and 15wt% MnO2 respectively. These bandgap values were obtained from kebulka-monk plots made by the reflectance readings of the UV/VIS.
Keywords: Doping, conductivity, TiO2, bandgap