Characterization of charge transport via in situ potentiometry in bulk heterojunction organic photovoltaic materials

摘要

The most promising active material for organic photovoltaic (OPV) cells is the polymer/fullerene bulk heterojunction(BHJ) system, but charge transport and recombination mechanisms in these materials have yet to be completelyunderstood. We report the use of lateral bulk heterojunction devices to perform novel material diagnostics on the BHJsystem. Using electron beam lithography, we fabricate devices with up to 24 voltage probes embedded in the channel inorder to perform in situ potentiometry. From current vs. voltage measurements performed at a variety of light intensities,we are able to describe the charge transport properties in three distinct regions of a polymer/fullerene BHJ device anddetermine the dominant recombination mechanism of the OPV material. We note that these are the first suchmeasurements performed on OPV materials. Such measurements will be very useful for materials diagnostics.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.