Phonon-assisted nonradiative energy transfer from colloidal quantum dots to monocrystalline bulk silicon

Date
2012
Advisor
Instructor
Source Title
IEEE Photonics Conference 2012
Print ISSN
1092-8081
Electronic ISSN
Publisher
IEEE
Volume
Issue
Pages
760 - 761
Language
English
Type
Conference Paper
Journal Title
Journal ISSN
Volume Title
Abstract

Silicon is one of the most dominant materials in photovoltaics. To increase optical absorption of silicon solar cells, colloidal quantum dots (QDs) have been proposed as a good sensitizer candidate owing to their favorably high absorption cross-section and tunable emission and absorption properties. To this end, QD sensitization of silicon has previously been studied by mostly facilitating radiative energy transfer (RET) [1,2]. Although RET based sensitization has achieved a considerable increase in conversion efficiencies in silicon photovoltaics, RET is fundamentally limited due to the effective coupling problem of emitted photons to silicon. Alternatively, nonradiative energy transfer (NRET), which relies on near field dipole-dipole coupling [3], has been shown to be feasible in sensitizer-silicon hybrid systems [4-8]. Although colloidal QDs as a sensitizer have been used to facilitate NRET into silicon, the detailed mechanisms of NRET to an indirect bandgap nonluminecent material, together with the role of phonon assistance and temperature activation, have not been fully understood to date. In this study, we propose a QD-silicon nanostructure hybrid platform to study the NRET dynamics as a function of temperature for distinct separation thicknesses between the donor QDs and the acceptor silicon plane. Here, we show NRET from colloidal QDs to bulk Si using phonon assisted absorption, developing its physical model to explain temperature-dependent lifetime dynamics of NRET in these QD-Si hybrids. © 2012 IEEE.

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Keywords
Absorption cross-section, Absorption property, Bulk silicon, Colloidal quantum dots, Dipole-dipole couplings, Effective coupling, Emitted photons, Hybrid platform, Monocrystalline, Near fields, Nonradiative energy transfer, Phonon assisted, Photovoltaics, Physical model, Radiative energy transfer, Temperature dependent, Tunable emissions, Conversion efficiency, Dynamics, Energy transfer, Hybrid systems, Phonons, Photonics, Semiconductor quantum dots, Single crystals, Silicon
Citation
Published Version (Please cite this version)