COLL 366 |
| We study organic/organic and organic/inorganic interfaces in polymer solar cells using time-resolved Electrostatic Force Microscopy (trEFM), and photoconductive Atomic Force Microscopy (pcAFM). These techniques allow us to measure charge generation, collection, and trapping with sub-100 nm resolution so we can correlate variations in performance directly with variations in local film morphology. This talk will describe our trEFM and pcAFM studies of polymer/polymer and polymer/fullerene solar cells. In model blends of polyfluorenes we present evidence that the majority of the collected photocurrent arises away from the visible domain interfaces, and also use trEFM to map local trapping and recombination centers. In polymer/fullerene cells we show that even the best devices exhibit a distribution of local quantum efficiencies and fill factors that vary on two characteristic length scales and that device performance can be improved by improving the uniformity of the anode contact. |
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Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
8:20 AM-11:40 AM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 226, Oral
Division of Colloid & Surface Chemistry |