The paper reports ultra-efficient multiple exciton generation (MEG) in colloidal PbSe and PbS quantum dots (QDs), achieving quantum yields of 300% for single-photon absorption. The study uses transient absorption spectroscopy to measure intraband and interband probe energies, indicating that the threshold photon energy for MEG is twice the lowest exciton absorption energy. The authors introduce a new model for MEG based on the coherent superposition of multiple excitonic states, suggesting that the formation of multiple electron-hole pairs per absorbed photon can enhance photovoltaic conversion efficiency. They also discuss the influence of the biexciton effect on early-time transient absorption data and present experimental and theoretical values of size-dependent interband transition energies for PbSe QDs. The findings highlight the potential of MEG in improving the efficiency of solar cell devices.The paper reports ultra-efficient multiple exciton generation (MEG) in colloidal PbSe and PbS quantum dots (QDs), achieving quantum yields of 300% for single-photon absorption. The study uses transient absorption spectroscopy to measure intraband and interband probe energies, indicating that the threshold photon energy for MEG is twice the lowest exciton absorption energy. The authors introduce a new model for MEG based on the coherent superposition of multiple excitonic states, suggesting that the formation of multiple electron-hole pairs per absorbed photon can enhance photovoltaic conversion efficiency. They also discuss the influence of the biexciton effect on early-time transient absorption data and present experimental and theoretical values of size-dependent interband transition energies for PbSe QDs. The findings highlight the potential of MEG in improving the efficiency of solar cell devices.