ITO nanoparticle film as a hole-selective layer for PbS-sensitized photocathodes

Photocathodes sensitized by photoactive semiconductors are of great significance for photoelectrochemical hydrogen evolution and tandem solar cells, yet their development is hindered by the scarcity of appropriate materials to serve as a hole-selective layer. In this work, we report a novel photocathode employing PbS as the photoactive material and tin-doped indium oxide (ITO) as the hole-selective layer. The optimized electrode showed a photocurrent of −75 μA cm−2 under light illumination at −0.222 V vs. Ag/AgCl with operational activity for 9 hours. The key factors for hole transfer were investigated. These results showed ITO to be a promising hole-transfer material for photoelectrochemical photocathodes.