The Effect of MgO on the Enhancement of the Efficiency in Solid-State Dye Sensitized Photocells Fabricated with SnO2 and CuI

Solid-state dye-sensitized photo cells were fabricated with nanocrystalline SnO2 covered with a thin layer of MgO as the anode and the hole conductor CuI as the cathode. While the cell fabricated with SnO2/Ruthenium bipyridyl dye/CuI delivered almost no photocurrent with very low photovoltage, the cell SnO2 (MgO)/Ruthenium bipyridyl dye/CuI delivered a short circuit photocurrent of ~2.5 mA cm-2 with an open circuit voltage of ~500 mV. Enhancement in the photocurrent and the voltages was found when the percentage of MgO to SnO2 was around 4 wt%. This is due to the formation of a thin energy barrier, which suppresses the recombination of photoelectrons.