Ultrafast carrier dynamics in PbS quantum dots

► Ultrafast carrier dynamics in PbS Quantum Dots (QDs) was characterized. ► Multiple exciton generation (MEG) and hot carrier cooling dynamics was clarified. ► We found that MEG began in as fast as 200 fs and completed around 3 ps. ► MEG occurred for photon energy larger than 2.7 times bandgap of the PbS QDs. ► Auger recombination dynamics of the generated multi-excitons were confirmed.