Nonradiative exciton energy transfer in hybrid organic-inorganic heterostructures

Abstract

Non-radiative optical energy transfer from a GaAs quantum well to a thin overlayer of an infrared organic semiconductor dye is unambiguously demonstrated. The dynamics of exciton transfer are studied in the time-domain using pump-probe spectroscopy at the donor site and fluorescence spectroscopy at the acceptor site. The effect is observed as simultaneous increase of the population decay rate at the donor and of the rise time of optical emission at the acceptor sites. The hybrid configuration under investigation provides an alternative nonradiative, non-contact pumping route to electrical carrier injection that overcomes the losses imposed by the associated low carrier mobility of organic emitters.

Dependence of Resonance Energy Transfer on Exciton Dimensionality

“…Therefore, the accelerated PL decay rate in the hybrid configuration can be attributed to RET mediated via near field dipolar coupling between the excitonic transition dipole moment and the polarizability of the organic layer. RET to the polyfluorene acts as an additional pumping source that can be identified on the rise time of the polyfluorene's PL dynamics [8]. Here, the polyfluorene is also directly optically excited by the laser pulse at 266 nm [see Fig.…”

An Inorganic/Organic Semiconductor “Sandwich” Structure Grown by Molecular Beam Epitaxy

“…In order to benefit from the complementary properties of the two material systems, electronic coupling across the inorganic/organic interface is required. Nonradiative energy transfer [1][2][3][4] as well as charge-carrier separation [5] could be observed on properly designed specimens. These findings are not only interesting from a fundamental point of view, but are also of direct practical relevance.…”

“…One approach employs wet-chemically produced semiconductor nanocrystals, the other relies on epitaxial semiconductor quantum well (QW) structures. For the latter, ZnO/ZnMgO, [1] InGaN/GaN, [2] and GaAs/ AlGaAs [3] have been employed successfully. High purity standards and excellent structural control are merits of epitaxial growth.…”

Surface plasmons mediated energy transfer from a semiconductor quantum well to an organic overlayer

“…4 for a review of relevant work). Following early theoretical predictions [5][6][7][8] , the energy transfer process has been observed from a quantum well to a quantum dot overlayer 9,10 , and from a quantum well to an organic overlayer [11][12][13] . A way to further improve the transfer between both components is the use of a plasmonic resonance to enhance the electric field in the system and take advantage of the metallic cathode which is often mandatory in electrical devices.…”