Boosting the efficiency of aqueous solar cells: A photoelectrochemical estimation on the effectiveness of TiCl 4 treatment

Increasing the photocurrent is one of the main objectives of the current research on aqueous photovoltaic cells, the emerging green, alternative technology in solar energy conversion devices. In such a scenario, this work deals with the thorough understanding of the electrochemical and photoelectrochemical effects of the TiCl 4 treatment onto TiO 2 electrodes, a well-known process for traditional dye-sensitized solar cells, and here, to our knowledge, investigated for the first time in water-based systems. From the quantitative evaluation of the photoelectrochemical parameters, it emerges that the TiCl 4 treatment beneficially affects the photovoltaic parameters: it doubles the sunlight conversion efficiency values, inhibits the recombination of photogenerated electrons with oxidized redox mediator ions, and ensures stable and reproducible cell performance at the laboratory scale.