Figure 1: Ultra-slow hot-carrier cooling in perovskites NCs.
From: Slow cooling and highly efficient extraction of hot carriers in colloidal perovskite nanocrystals
(a) Pseudo colour TA plot (upper panel) and normalized TA spectra (lower panel) for medium MAPbBr3 NCs (radii ∼4–5 nm) in solution at low pump fluence (left panel) with initially generated <N0> ∼0.1 (n0avg∼2.6 × 1017 cm−3) and high pump fluence (right panel) with <N0> ∼2.5 (n0avg∼6.5 × 1018 cm−3). (b) Pseudo colour representation (upper panel) and normalized TA spectra (lower panel) for MAPbBr3 bulk film at low pump fluence (left panel) with initially generated carrier density n0∼2.1 × 1017 cm3 and high pump fluence (right panel) with n0 ∼1.5 × 1019 cm3. (c) Hot-carrier temperature as a function of delay time for the medium MAPbBr3 NCs and bulk film with different carrier densities. Photoexcitation energy for a,b is 3.1 eV.
