1 research outputs found
Core/Alloyed-Shell Quantum Dot Robust Solid Films with High Optical Gains
We report high optical gain from
freestanding, optically stable,
and mechanically robust films that are loaded with cross-linked CdSe/Cd<sub>1–<i>x</i></sub>Zn<sub><i>x</i></sub>Se<sub>1–<i>y</i></sub>S<sub><i>y</i></sub> core/alloyed
shell quantum dots (QD). These solid films display very high net optical
gain as high as 650 cm<sup>–1</sup> combined with a low pump
excitation gain threshold of 44 μJ/cm<sup>2</sup>. The functionalization
of the QDs using short-chain bifunctional cross-linkers not only significantly
improves the net optical gain by allowing for a nearly 2-fold increase
in QD loading but also provides stable passivation of the QDs which
imparts excellent thermal stability, mechanical robustness, and stability
under harsh chemical environments. The gain achieved here is up to
3-fold higher than that typically reported for traditional drop-cast
QD films. Moreover, stable photoluminescence over long shelf storage
time is a distinguished characteristic of the films. The QD films
fabricated here span large areas (several cm<sup>2</sup>), can be
readily micropatterned and sustain multiple harsh chemical treatment.
Furthermore, they can be readily transferred onto different substrates
without compromising their structural integrity and without diminishing
optical activity that opens the paths to design complex and robust
gain–loss optical structures