Graphene-Quantum Dot Hybrid Optoelectronics at Visible Wavelengths

With exceptional
electronic and gate-tunable optical properties,
graphene provides new possibilities for active nanophotonic devices.
Requirements of very large carrier density modulation, however, limit
the operation of graphene based optical devices in the visible spectrum.
Here, we report a unique approach that avoids these limitations and
implements graphene into optoelectronic devices working in the visible
spectrum. The approach relies on controlling nonradiative energy transfer
between colloidal quantum-dots and graphene through gate-voltage induced
tuning of the charge density of graphene. We demonstrate a new class
of large area optoelectronic devices including fluorescent display
and voltage-controlled color-variable devices working in the visible
spectrum. We anticipate that the presented technique could provide
new practical routes for active control of light–matter interaction
at the nanometer scale, which could find new implications ranging
from display technologies to quantum optics.