Researchers from Northwestern University in Illinois (USA) have published in Nature a novel solid state Dye-sensitized solar cell (DSC) that shows an outstanding efficiency higher than 10 %, very close to the best DSC value of around 11 % from their liquid counterpart. The cell has the classic structure for the photoanode (FTO/TiO2/dye) and the electrolyte is substituted by a solution processable p-type semiconductor (CsSnI3 doped with SnF).
Up to now, the best solid-state DSCs were made of hole transport materials such as spiro-OMeTAD or bis-EDOT, providing efficiencies around 6 %, whose main problem are related to the poor filling of the nanoporous TiO2 layer. This novel cell proposed by Mercouri Kanatzidis and co-workers fills easily the nanoporous matrix since the hole conductor, dissolved in a volatile organic solvent, is injected directly onto the sensitized photoelectrode. This facile and inexpensive process in addition to the use of abundant elements in the fabrication of the device make this new cell a breakthrough in the solar cell area and a feasible solution to the leaking problems of liquid DSCs.
