The influence of illumination on two-photon absorption of quantum dots

Abstract

The influence of illumination with 365[Formula: see text]nm ultraviolet light on two-photon absorption (TPA) of aqueous Co[Formula: see text] doped CdTe (CdTe:Co) quantum dots (QDs) is studied. The results show that with the increase of illumination time, the TPA cross section of the CdTe:Co QDs increases. The experimental results suggest that this enhancement is due to the reduction of surface nonradiative traps which is consistent with the formation of CdS shell on the surface of CdTe:Co QDs. Meanwhile, the results indicate that aqueous CdTe:Co QDs have good optical limiting and optical stabilization performances. This provides a strategy of TPA enhancement by illumination.