1：Experimental Design and Method Selection:

The study involved the synthesis of a new fullerene derivative, PCPB, and its formulation with PCBM to create hybrid ETLs. The methodology included single-crystal X-ray diffraction to understand intermolecular interactions and packing of fullerene derivatives.

2：Sample Selection and Data Sources:

Samples included pure PCBM, pure PCPB, and their mixtures in varying weight ratios. Data were acquired through photovoltaic performance tests, thermal stability tests, and morphological analysis.

3：List of Experimental Equipment and Materials:

Instruments used included a Bruker Biospin Advance III 500 MHz for NMR, UV-2550 spectrometer for UV-Vis absorption, Perkin-Elmer Pyris 6 for TGA, and Rigaku Ultima IV for XRD. Materials included PCBM, PCPB, and other chemicals purchased from Alfa Aesar or Sigma Aldrich.

4：Experimental Procedures and Operational Workflow:

The experimental process involved the fabrication of PSCs with different ETLs, thermal aging tests, and performance evaluation under simulated solar irradiation.

5：Data Analysis Methods:

Data analysis included the evaluation of photovoltaic parameters, electron mobility measurements using the SCLC method, and EIS measurements to assess charge transfer resistance.