1：Experimental Design and Method Selection:

The study involved the synthesis of core/shell-structured TiO2/PbS photoanodes by compositing different cycles of PbS CQDs on m-TiO

2：A modified hot-injection method was applied to synthesize PbS CQDs. The perovskite film was deposited onto the bare TiO2 electrode and TiO2/PbS electrode by a conventional two-step spin-coating method. Sample Selection and Data Sources:

The samples were denoted as PbS-x/CsPbBr3, where x is related to the deposition of PbS CQDs on m-TiO

3：List of Experimental Equipment and Materials:

Equipment included transmission electron microscopy (TEM; FEI Titan G2 ETEM), scanning electron microscopy (SEM; Hitachi SU8020), X-ray diffraction (XRD; Rigaku/SmartLab), UV–vis absorption spectra (Shimadzu 2700 spectrophotometer), X-ray photoelectron spectra (ESCALAB 250XI X-ray photoelectron spectrometer), steady-state photoluminescence (PL; HORIBA FluoroMax-4), and a solar simulator (SCS10X150, Zolix, China) with a Keithley 2400 Source Meter.

4：Experimental Procedures and Operational Workflow:

The TiO2 ETL was prepared by spin-coating on fluorine-doped tin oxide (FTO). The perovskite film was deposited by conventional two-step spin-coating method.

5：Data Analysis Methods:

The crystalline structure was evaluated by XRD, UV–vis absorption spectra were recorded, and the current–voltage (J–V) plots of the PSC devices were detected under AM 1.5 G simulated solar illumination.