Two-photon absorption and efficient encapsulation of near-infrared-emitting CdSexTe1−x quantum dots

- Synthesis of the IR emitting alloyed CdSexTe1−x quantum dots has been performed.
- Two-photon absorption cross section of the CdSexTe1−x QDs was measured in the IR range.
- The QDs were encapsulated into Brij 58® micelles and transferred to the aqueous environment.
- A blue-shift of fluorescence of QDs in the micelles was observed.

Hydrophobic CdSexTe1−x quantum dots with near infrared emission in the 700-750 nm range were synthesized by a wet chemistry technique. Their nonlinear optical properties were studied using Z-scan technique with a tunable femtosecond laser system. The peak value of the two-photon absorption cross section was found to be ∼2400 GM at 1400 nm. To demonstrate a possible way of utilizing the CdSexTe1−x quantum dots in aqueous environment we describe here a convenient method of preparation of Brij 58® micellar systems loaded with the quantum dots. The obtained nanoconstructs were characterized using optical spectroscopy, TEM and DLS. The micelles colloidal stability, and the influence of the encapsulation process on the spectroscopic properties of the quantum dots are discussed. In particular, we have observed a 60 nm blue-shift of the emission maxima upon loading quantum dots inside the micelles.