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E Ehrenfreund

Publications and source records attributed to E Ehrenfreund.

18 recordsLinked to original sources
PubMed2003

Linear and nonlinear photoexcitation dynamics in pi-conjugated polymers.

Linear and nonlinear recombination kinetics with various lifetime distributions were identified for long-lived photoexcitations in a series of pi-conjugated polymer films using modulation frequency and excitation intensity dependencies of the photoinduced absorption. This includes monomolecular, bimolecular, and defect-limited recombination processes that lead to saturation. Using generalized kinetics parameters, we found characteristic plots for all recombination processes. Specifically, the bimolecular recombination process shows superlinear intensity dependence away from the steady state; on the contrary, dispersive bimolecular recombination leads to sublinear dependence.

Journal Article↗
PubMed2001

Semiconductor quantum dot: a quantum light source of multicolor photons with tunable statistics.

We investigate the intensity correlation properties of single photons emitted from an optically excited single semiconductor quantum dot. The second order temporal coherence function of the photons emitted at various wavelengths is measured as a function of the excitation power. We show experimentally and theoretically that a quantum dot is not only a source of nonclassically correlated monochromatic photons but is also a source of multicolor photons with tunable correlation properties. We found that the emitted photon statistics can be varied by the excitation rate from a sub-Poissonian one, where the photons are temporally antibunched, to super-Poissonian, where they are temporally bunched.

Journal Article↗