CrOOH as high-performance surface passivation material for dye-sensitized solar cell

α-CrOOH was firstly explored as a passivation material for p-type dye-sensitized solar cell based on 3R-CuCrO2 delafossite and its beneficial effect on photovoltaic performance of p-type DSSC was demonstrated. α-CrOOH nanomaterial was obtained by a simple hydrothermal method using strong acid solution. The n-type α-CrOOH passivation of the p-type 3R-CuCrO2 film has provided a doubling of JSC and a threefold increase in the VOC compared to the pure 3R-CuCrO2 photocathode in DSSC. This remarkable enhancement could be explained in that α-CrOOH layer acts as a barrier layer for charge recombination between the holes in the valence band and the electrolyte or dye. In addition, formed p-n junction would facilitate the charge separation. Therefore, the α-CrOOH is proposed as a promising material to modify the photocathode of p-type DSSC with excellent photovoltaic efficiency.