Exciton interaction with a spatially defined charge accumulation layer in the organic semiconductor diindenoperylene

Abstract

We present an investigation of the microscopic interplay between excitons and charge carriers by means of combined photoluminescence (PL) and charge carrier transport measurements on organic thin film transistors (OTFTs). For this purpose, the prototypical organic semiconductor diindenoperylene was utilized as the active material. The OTFT accumulation layer provides a spatially defined interaction zone for charges and photogenerated excitons leading to a PL intensity reduction of up to 4.5$%$. This effect correlates with the accumulated hole carrier density and provides a lower estimate of about $1.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ cm${}^{3}$/s for the recombination rate of nonradiative exciton-hole processes. It is rationalized that these processes are preferentially mediated by trapped holes.