In order to better understand the effects of morphology on polymer-fullerene based organic photovoltaic devices (OPV), analysis is performed using a dynamic Monte Carlo simulation to study both the exciton and charge behavior. Theoretical morphologies are generated through the use of a modified Ising model which incorporates neutron reflectometry data, and these structures are then characterized and refined through the use of simulated small angle neutron scattering (SANS). A novel technique for quickly calculating the simulated SANS profile of a model, referred to as the distribution function method (DFM), is motivated and introduced.We generate percolating fullerene/polymer bulk heterostructures that are consistent with experimental characterization of the nanostructure, in particular neutron reflectometry and small angle neutron scattering data from as cast and annealed poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) systems. Dynamic Monte Carlo transport calculations using these morphologies correlate changes in exciton dissociation efficiency and charge collection efficiency with morphological features including characteristic domain size, fullerene concentration profile, degree of fullerene dispersion, and the impact of polymer fiber crystallization.
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