1：Experimental Design and Method Selection:

The study involved the synthesis of oleic acid covered PbS QDs via a hot-injection method, followed by ligand exchange using a triple cation perovskite precursor. The QDs were then used to fabricate photovoltaic devices with a structure of Glass/ITO/ZnO/PbS/EDT-PbS/Au.

2：Sample Selection and Data Sources:

Oleic acid covered PbS QDs were synthesized and subjected to ligand exchange. The resulting QDs were characterized using various spectroscopic and microscopic techniques.

3：List of Experimental Equipment and Materials:

Equipment included a JASCO UV-Vis V670 spectrometer for UV-Vis spectroscopy, a JASCO FT/IR-4600 spectrometer for FTIR spectroscopy, a Thermo Scientific ESCALAB 250 Xi spectrometer for XPS, a Rigaku SmartLab diffractometer for XRD, a JSM-7610F FEG-SEM for SEM imaging, and a FEI Tecnai 20 for TEM imaging. Materials included PbS QDs, perovskite precursors (CsI, MAI, FAI, PbI2, PbBr2), and solvents (DMF, DMSO, octane, toluene, butylamine).

4：Experimental Procedures and Operational Workflow:

The ligand exchange process involved mixing the perovskite precursor with OA-PbS QDs, washing, and re-dispersion in butylamine. The QDs were then spin-coated to form the active layer of the photovoltaic devices, followed by annealing and deposition of additional layers.

5：Data Analysis Methods:

Data from UV-Vis, FTIR, XPS, XRD, SEM, and TEM were analyzed to confirm perovskite shell formation and characterize the QDs. Photovoltaic performance was evaluated using current-density vs voltage sweeps under AM1.5G illumination.