Examining Forster energy transfer for semiconductor nanocrystalline quantum dot donors and acceptors

TitleExamining Forster energy transfer for semiconductor nanocrystalline quantum dot donors and acceptors
Publication TypeJournal Article
Year of Publication2008
AuthorsCurutchet, C, Franceschetti A, Zunger A, Scholes GD
JournalJournal of Physical Chemistry C
Volume112
Issue35
Pagination13336 - 13341
Date Published2008
ISBN Number1932-7447
Keywordsconjugated polymers, couplings, density cube method, Dynamics, exciton, pigments, solids, systems
AbstractExcitation energy transfer involving semiconductor quantum dots (QDs) has received increased attention in recent years because their properties, such as high photostability and size-tunable optical properties, have made QDs attractive as Forster resonant energy transfer (FRET) probes or sensors. An intriguing question in FRET studies involving QDs has been whether the dipole approximation, commonly used to predict the electronic coupling, is sufficiently accurate. Accurate estimates of electronic couplings between two 3.9 nm CdSe QDs and between a QD and a chlorophyll molecule are reported. These calculations are based on transition densities obtained from atomistic semiempirical calculations and time-dependent density functional theory for the QD and the chlorophyll, respectively. In contrast to the case of donor-acceptor molecules, where the dipole approximation breaks down at length scales comparable to the molecular dimensions, we find that the dipole approximation works surprisingly well when donor and/or acceptor is a spherical QD, even at contact donor-acceptor separations. Our conclusions provide support for the use of QDs as FRET probes for accurate distance measurements.