1：Experimental Design and Method Selection:

The study involved fabricating potassium-doped and undoped perovskite solar cells (PSCs) to compare their photovoltaic performance and stability. The doping was achieved by adding 0.02 mol KI to a 1.2 М perovskite precursor solution.

2：02 mol KI to a 2 М perovskite precursor solution. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: The samples included PSCs with doped photoactive perovskite layers and reference PSCs based on undoped systems. The architecture of the PSCs was glass/FTO/TiO2/CH3NH3(Pb:K)I3/spiro-MeOTAD/Au.

3：List of Experimental Equipment and Materials:

Equipment used included a Hitachi SU8000 scanning electron microscope (SEM) for surface morphology examination, a DRON-3 powder diffractometer for structural characteristics, an Abet Technologies solar simulator for PV parameters measurement under standard АМ1.5G illumination, a Keithley 4200-SCS analyzer for J–V characteristics measurement, and an automated QEX10 system for IPCE spectra recording.

4：5G illumination, a Keithley 4200-SCS analyzer for J–V characteristics measurement, and an automated QEX10 system for IPCE spectra recording. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The PSCs were fabricated under ambient air conditions. The surface morphology and structural characteristics of the perovskite layers were examined. The PV parameters were measured, and the operational stability was examined by periodically measuring the J–V characteristics over 45 days.

5：Data Analysis Methods:

The data analysis involved comparing the J–V characteristics, IPCE spectra, and operational stability of doped and undoped PSCs.