The features of nonlinear absorption of two-photon excited excitons in CdSe/ZnS quantum dots

► Two-photon resonant absorption of excitons was measured in CdSe/ZnS quantum dots. ► Two methods were used: traces of luminescence and nonlinear transmission measurement. ► Discovered features of two-photon absorption at high excitation were explained. ► State filling and Stark effects accompany two-photon absorption of excitons. ► Extinction of luminescence arises due to dominating Auger recombination.