We report highly efficient, simultaneous fluorescence and phosphorescence (74% yield) at room temperature from a single molecule ensemble of (BzP)PB dispersed into a polymer host. The slow phosphorescence (208 ms lifetime) is very efficient (50%) at room temperature and only possible because the non-radiative rate for the triplet state is extremely low. The ability of an organic molecule to function as an efficient dual state emitter at room temperature is unusual and opens new fields of applications including the use as broadband down-conversion emitters, optical sensors and attenuators, exciton probes, and spin-independent intermediates for F\"orster resonant energy transfer.
Cite
@article{arxiv.1308.0036,
title = {Highly efficient, dual state emission from an organic semiconductor},
author = {Sebastian Reineke and Nico Seidler and Shane R. Yost and Ferry Prins and William A. Tisdale and Marc A. Baldo},
journal= {arXiv preprint arXiv:1308.0036},
year = {2015}
}