Surface modification of TiO 2 nanostructured films by inserting Mg 2+ ions applied to dye sensitized solar cells

Abstract

Nanostructured electrodes were prepared based on titanium dioxide (TiO 2 ) modified by incorporating small amounts of magnesium oxide (MgO) to improve their efficiency in dye sensitized solar cells. J-V curve measurements show efficiencies increased from 2.32 to 2.55 % with the addition of MgCl 2 . On the other hand, the incident photon-to-current efficiency (IPCE) measures obtained show an improvement with the addition of magnesium oxide. This is in agreement with absorbance results and short circuit current values. Values from cyclic voltammetry curves show that surface modification caused energy levels to increase below the TiO 2 conduction band by incorporating magnesium oxide. Electrochemical impedance spectroscopy confirmed the presence of these additional energy levels and gave evidence of increased recombination in the TiO 2 film and decreasing electron lifetime from 15.95 to 6.82 ms.