Fig. 2: Time-Resolved Signatures of Hot Carrier-induced Trapping.

a Transient Absorption spectrum of MAPbI₃ NCs in anhydrous toluene solutions under intense (<N > = 3.6 e–h) high-energy excitation of 3.10 eV (around 1.4 eV in excess of the bandgap). Under this intense excitation, biexponential cooling dynamics is observed and reveals the coexistence of Auger and phonon-mediated relaxation pathways²⁴. Inset: Corresponding hot carrier temperatures (black squares), estimated using the Boltzmann model. Multi-exponential fit is represented by the brown line. b Pump-push-probe differential spectrum of MAPbI₃ NCs in anhydrous toluene solutions, pumped at 2.07 eV (10 µJ cm⁻², <N> = 0.88), probed over the 1.60–1.90 eV interval, and pushed at 1.03 eV (1 mJ cm⁻²). The black dashed line represents the push time-zero, the positive ΔΔT signal (blue) implies a decrease in the PB signal, and a negative ΔΔT signal (red) an increase in the PB signal. c Pump-probe (PP) and pump-push-probe (PPP) kinetics pumped at 1.91 eV (10 µJ cm⁻², <N> = 0.8) and probed at 1.70 eV, with push energy of 1.03 eV (1 mJ cm⁻²). Thin lines represent the experimental data, and thick lines are exponential model fits to the data.