Fig. 4: Light absorption and charge transport properties of PSCs.

a UV−Vis absorption spectra of CsPbI3 QD film, perovskite films W/O and W/ CsPbI3 QDs. b Photoluminescence spectra and c Time-resolved photoluminescence decay curves of perovskite films W/O and W/ CsPbI3 QDs. d Electrochemical impedance responses of PSC devices W/O and W/ CsPbI3 QDs measured at an open-circuit voltage under dark conditions at a 0.8 V bias