Exciton diffusion length in the organic semiconductor diindenoperylene

Abstract

The photovoltaic behavior of Schottky barrier devices consisting of a single diindenoperylene (DIP) layer sandwiched between an indium tin oxide and Ag electrode has been investigated. Correlating the spectral dependence of the photocurrent and the absorption coefficient, we estimated the exciton diffusion length in DIP to ∼100nm along the c′ direction. X-ray structural analysis yielded this length to be in agreement with the average crystallite size, thereby, revealing domain boundaries to be the limiting effect on the exciton transport. The corresponding exciton diffusion constant of 5×10−3cm2∕s resembles that of highly ordered single crystals of polyaromatic hydrocarbons.