We show that the method we have developed for measuring the singlet exciton diffusion length in blends with [6,6]-phenyl-C 61-butyric acid methyl ester (PCBM) can be applied not only to polymeric materials, but also to small molecule organic semiconductors. Small organic molecules have a large potential for molecular re-organization upon thermal annealing. Here we show that the exciton diffusion length is decreased upon annealing from 9 to 3 nm in a thin film of a diketopyrrolopyrrole derivative. Such a variation is attributed to exciton delocalization effects in the crystalline domains that are formed during the annealing process as well as to the exciton quenching at grain boundaries.
|Number of pages||6|
|Journal||Physical Chemistry Chemical Physics|
|State||Published - Nov 7 2012|
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry