Low-threshold stimulated emission using colloidal quantum wells.
The use of colloidal semiconductor nanocrystals for optical amplification and lasing has been limited by the need for high input power densities. Here we show that colloidal nanoplatelets produce amplified spontaneous emission with thresholds as low as 6 μJ/cm(2) and gain as high as 600 cm(-1), both a significant improvement over colloidal nanocrystals; in addition, gain saturation occurs at pump fluences 2 orders of magnitude higher than the threshold. We attribute this exceptional performance to large optical cross-sections, slow Auger recombination rates, and narrow ensemble emission line widths.
Department of Chemistry and James Frank Institute, University of Chicago , Chicago, Illinois 60637, United States.
Chunxing
C
She
Igor
I
Fedin
Dmitriy S
DS
Dolzhnikov
Arnaud
A
Demortière
Richard D
RD
Schaller
Matthew
M
Pelton
Dmitri V
DV
Talapin