Aspect Ratio and Quantum Confinement Tunable Giant Two-Photon Absorption from 1D CsPbI(3) Perovskite Nanorods.

Herein, we investigate the influence of aspect ratio and quantum confinement on the single-photon (σ(1)) and two-photon absorption cross-section (σ(2)) for perovskite CsPbI(3) nanorod (NR). Notably, experimentally measured data show extremely high σ(2) for CsPbI(3) NR (10.8 × 10(7) GM) which is five orders of magnitude higher than organic chromophores, and two order of magnitude higher than CsPbBr(3) nanocrystals. Moreover, σ(2) for NRs can be enhanced by two-orders of magnitude by varying the aspect ratio and σ(1) enhances linearly with aspect ratios. Furthermore, experimental data show moderate quantum confinement effect on the volume-normalized σ(1) and σ(2) for nanorods.