1：Experimental Design and Method Selection:

The study involved the synthesis of fluorinated reduced graphene oxide (F5-rGO) from graphene oxide (GO) using pentafluorophenylhydrazine under mild conditions. The F5-rGO was then used as HTL in OSCs based on the PTB7:PC71BM blend. The top electrode was Field’s metal, deposited vacuum-free.

2：Sample Selection and Data Sources:

The materials used included flake graphite, sulfuric acid, phosphoric acid, potassium permanganate, hydrogen peroxide, pentafluorophenylhydrazine, phenylhydrazine, PEDOT:PSS, PTB7, PC71BM, and Field’s metal.

3：List of Experimental Equipment and Materials:

Equipment included a JEOL (JSM-7800F) microscope for SEM, Renishaw InVia microscope Raman spectrometer, Agilent Technologies model Cary 670 FTIR spectrometer, Nanosurf EasyScan2 AFM, SmartSPM-1000 AFM for KPFM, TGA Q500 TA Instruments for thermogravimetric analyses, and Phi5000 Versa Probe II for XPS analyses.

4：Experimental Procedures and Operational Workflow:

The GO was synthesized using a modified Hummers method. F5-rGO was prepared by dispersing GO in water and adding pentafluorophenylhydrazine. OSCs were fabricated with different HTLs and characterized using J-V curves under AM

5：5 spectrum. Data Analysis Methods:

The photovoltaic parameters JSC, VOC, FF, and PCE were determined from J-V plots. The work function of F5-rGO was determined by KPFM.