Nonlinear light absorption in colloidal CdSe/CdS nanoplatelets

TL;DR

This study explores the nonlinear optical behavior of CdSe/CdS nanoplatelets near exciton resonances using pump-probe techniques, revealing exciton scattering and absorption saturation with theoretical insights into exciton dynamics.

Contribution

It provides new experimental data and theoretical analysis on exciton dynamics and nonlinear light absorption in colloidal CdSe/CdS nanoplatelets.

Findings

Observed exciton scattering between heavy- and light-hole states

Detected saturation of light absorption in nanoplatelets

Determined parameters of exciton dynamics

Abstract

We investigated the nonlinear optical properties of CdSe/CdS nanoplatelets in the vicinity of heavy hole and light hole exciton resonances. The two color pump-probe technique was applied. The first intense pulse created non-equilibrium exciton population, which was detected as a decrease of probe light absorption. We observed intense scattering of excitons between heavy- and light-hole excitonic states. We also studied experimentally saturation of absorption in nanoplatelets. Theoretical description of these phenomena allowed us to determine parameters of exciton dynamics in nanoplatelets.