Fig. 1

Pump–probe spectroscopy of lead iodide perovskite. a Absorption spectrum of lead iodide perovskite and broadband laser spectrum used for the degenerate pump–probe and 2D electronic spectroscopy (2DES) experiments. The pump spectrum overlaps with the free band continuum as well as the excitonic transition of perovskite. b Pump–probe spectroscopy of perovskite: ΔT/T spectrum as a function of probe wavelength and pump–probe delay (excitation density: 2 × 10¹⁸ cm⁻³). The broadband nature of the short pump pulses makes the observation of a non-thermalized distribution and thermalization difficult in pump–probe experiments. Inset: Pump–probe dynamics at 745 nm probe wavelength. The signal rises over two distinct timescales