Up-conversion fluorescence: noncoherent excitation by sunlight.
We demonstrate up-conversion of noncoherent sunlight realized by ultralow excitation intensity. The bimolecular up-conversion process in our systems relies on the presence of a metastable triplet excited state, and thus has dramatically different photophysical characteristics relative to the other known methods for photon up-conversion (two-photon absorption, parametric processes, second harmonic generation, sequential multiphoton absorption, etc.).
Baluschev
S
S
Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. balouche@mpip-mainz.mpg.de
Miteva
T
T
Yakutkin
V
V
Nelles
G
G
Yasuda
A
A
Wegner
G
G