Baluschev S, Miteva T, Yakutkin V, Nelles G, Yasuda A, Wegner G
Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Phys Rev Lett. 2006 Oct 6;97(14):143903. doi: 10.1103/PhysRevLett.97.143903. Epub 2006 Oct 4.
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.).
