Exciton-exciton annihilation and the production of interchain species in conjugated polymer films: comparing the ultrafast stimulated emission and photoluminescence dynamics of meh-PPV

摘要

The nature of the optically prepared excited-state(s) of conjugated polymer films is critical to the development of optoelectronic devices such as plastic light emitting diodes (PLEDs) and solar cells. Despite this, a fundamental understanding of the primary photoexcitation remains highly controversial. Since the photophysics of conjugated polymer films depend sensitively on excitation intensity, the degree of charge separation in the initially-prepared excited state and the role and origin of interchain electronic species can vary considerably under different experimental conditions, explaining the large number of conflicting results in the literature.