Highly efficient resonant coupling of optical excitations in hybrid organic/inorganic semiconductor nanostructures

Publication Type:

Journal Article

Source:

Nat. Nanotechnol., nature.com, Volume 2, Issue 9, p.555-559 (2007)

ISBN:

1748-3387

Keywords:

2007, 2013 and earlier

Abstract:

The integration of organic and inorganic semiconductors on the nanoscale offers the possibility of developing new photonic devices that combine the
best features of these two distinct classes of material. Such devices
could, for example, benefit from the large oscillator strengths found in
organic materials and the nonlinear optical properties of inorganic
species. Here we describe a novel hybrid organic/inorganic nanocomposite
in which alternating monolayers of J-aggregates of cyanine dye and
crystalline semiconductor quantum dots are grown by a layer-by-layer
self-assembly technique. We demonstrate near-field photon-mediated
coupling of vastly dissimilar optical excitations in the two materials
that can reach efficiencies of up to 98% at room temperature. By varying
the size of the quantum dots and thus tuning their optical resonance for
absorption and emission, we also show how the ability of J-aggregates to
harvest light can be harnessed to increase the effective absorption cross
section of the quantum dots by up to a factor of ten. Combining organic
and inorganic semiconductors in this way could lead to novel nanoscale
designs for light-emitting, photovoltaic and sensor applications.