Fig. 1. The preparation and properties of CsPbI₃ QD and CsPbI₃ QD/PCBM films.

a Schematic of the fabrication of pristine, control and hybrid CsPbI₃ QD films. b FTIR spectra of pristine, control, and hybrid films on SnO₂/ITO glass substrates (characteristic peaks of organic species are highlighted by the red background). c, d 2D time-wavelength-dependent TA color maps of the control and the hybrid CsPbI₃ QD films excited at 600 nm, the excitation fluence is 4.2 µJ/cm²/pulse. e Normalized TA dynamics of the ground-state bleach (GSB: 670 nm) for control and hybrid CsPbI₃ QD films. For the control film, the components are τ₁ = 1.3 ps, τ₂ = 52.3 ps, and τ₃ = 483.2 ps. For the hybrid film, the time components are extracted as τ₁ = 1.4 ps, τ₂ = 57.6 ps, and τ₃ = 312.8 ps.