Single-Exciton Gain and Stimulated Emission across the Infrared Telecom Band from Robust Heavily-doped PbS Colloidal Quantum Dots.
2020
Materials
with optical gain in the infrared are of paramount importance
for optical communications, medical diagnostics, and silicon photonics.
The current technology is based either on costly III–V semiconductors
that are not monolithic to silicon CMOS technology or Er-doped fiber
technology that does not make use of the full fiber transparency window.
Colloidal quantum dots (CQDs) offer a unique opportunity as an optical
gain medium in view of their tunable bandgap, solution processability,
and CMOS compatibility. The 8-fold degeneracy of infrared CQDs based
on Pb-chalcogenides has hindered the demonstration of low-threshold
optical gain and lasing, at room temperature. We demonstrate room-temperature,
infrared, size-tunable, band-edge stimulated emission with a line
width of ∼14 meV. Leveraging robust electronic doping and charge-exciton
interactions in PbS CQD thin films, we reach a gain threshold at the
single exciton regime representing a 4-fold reduction from the theoretical
limit of an 8-fold degenerate system, with a net modal gain in excess
of 100 cm–1.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
33
References
16
Citations
NaN
KQI