Impact of precursor solution temperature on two-step spin-coated FAPbI 3 film elucidated by surface morphology and in situ photoluminescence dynamics

Key Points

• To analyze how varying the temperature of precursor solutions affects the properties of two-step spin-coated FAPbI3 films.
• Investigated precursor solution temperatures of 50–70 °C for PbI2 and ∼25 °C for FAI.
• Utilized in situ photoluminescence to observe nucleation behavior during the film formation process.
• Examined surface morphology of resulting films to assess quality.
• Higher temperatures lead to better crystallization and morphology in FAPbI3 films.
• Specifically, compact α-phase films were achieved at indicated temperature ranges.