A microscopic model for the behavior of nanostructured organic photovoltaic devices

By R. Marsh, Chris Groves, N. Greenham. 2007

221 citations recorded by the source corpus.

We present a Monte Carlo model of carrier separation and recombination in nanostructured organic photovoltaic (OPV) devices which takes into account all electrostatic interactions, energetic disorder, and polaronic effects. This permits a detailed analysis of the strong morphology dependence of carrier collection efficiency. We find that performance is determined both by the orientation of the heterojunction relative to the external electric field as well as by carrier confinement due to polymer intermixing. The model predicts that an idealized interdigitated structure could achieve overall efficiencies twice as high as blends. The model also reproduces the weakly sublinear intensity dependence of short-circuit photocurrent (ISC) seen in experiment. We show that this is not the result of space-charge effects but of bimolecular recombination. Disconnected islands of polymer in coarser blends result in bimolecular recombination even at low intensities and should therefore be minimized. By including a micros...

Subfields: Electrical and Electronic Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/3f6e6956f0c7f6357302b46e7c3bad0c07c3d0ca