Fabrication and dye-sensitized solar cell performance of nanostructured NiO/coumarin 343 photocathodes

A nanostructured NiO electrode was synthesized through an initial deposition of layered basic nickel acetate having a yarn-ball-shaped morphology and subsequent heat-treatment at 500°C in oxygen. A sandwich-type open cell using a NiO/C343 photocathode yielded a photocurrent density of 1.61 mA cm-2, an open-circuit photovoltage of 113 mV, a fill factor of 0.31, and a solar energy conversion efficiency of 0.057%, reaching the highest level ever reported. A tandem solar cell was also produced together with a TiO2 /N719 photoanode, which resulted in an increase of the open-circuit photovoltage to 0.80 V.