Phosphating passivation layer for quantum dot sensitized solar cells

•Phosphating passivate photoanode surface.•Cell performances are enhanced.•Passivation is proved by electrochemical analyses. Surface passivation is a powerful route to enhance the photovoltaic performance of quantum dot sensitized solar cells. In the present work, we graft the well-established phosphating process in metal surface treating to form the passivation layer. The results show that the passivation layer formed by phosphate improves the photovoltaic performance of the solar cell significantly by inhibiting the internal charge recombination process. The charge transfer resistance (Rre) of the ZnPh passivated solar cell is 19.22 Ω with a champion power conversion efficiency (PCE) of 4.50 %. Compared to the PCE of 3.37 % with 5.97 Ω in Rre of the unpassivated reference cell, an efficiency enhancement of 33.5% is received.