Tunable light emissions of PEAI-doped FA0.6Cs0.4Pb(I0.6Br0.4)3 thin films via manipulating self-healing and phase segregation effects

Abstract

The near-infrared emission intensity of aged FA0.6Cs0.4Pb(I0.6Br0.4)3 mixed perovskite films are increased by more than 2 times via the surface passivation with phenethylammonium iodide (PEAI) molecules. When the PEAI concentration is 3 mg/mL, the near-infrared emission of the laser-induced mixed perovskite film is stable and fixed at the peak wavelength of about 740 nm after 20 s. The X-ray diffraction patterns, Urbach energy values, atomic-force microscopic images, and time-dependent two-photon photoluminescence (TPPL) spectra are used to understand the time-dependent PL spectra and enhanced PL intensity of the mixed perovskite thin films without and with the PEAI additives. Our findings provide a method to adjust the light emission wavelength of mixed perovskite thin films in the near-infrared wavelength range.