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Probing Charge Recombination Dynamics in Organic Photovoltaic Devices under Open‐Circuit Conditions |
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| Authors: | Lindsay C. C. Elliott James I. Basham Kurt P. Pernstich Pragya R. Shrestha Lee J. Richter Dean M. DeLongchamp David J. Gundlach |
| Affiliation: | 1. Materials Science and Engineering Division, Material Measurement Laboratory, NIST, Gaithersburg, MD, USA;2. Semiconductor and Dimensional Metrology Division, Physical Measurement Laboratory, NIST, Gaithersburg, MD, USA;3. Department of Electrical Engineering, Penn State University University Park, PA, USA;4. Institute of Computational Physics, Zurich University of Applied Sciences, ZHAW, Winterthur, Switzerland;5. Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA |
| Abstract: | Large perturbation transient photovoltage and impedance spectroscopy measurements are used to gain insights into recombination in organic photovoltaic devices. The combination of these two simple optoelectronic techniques enables characterization of recombination order as well as mobile and trapped charge evolution over a large range of carrier densities. The data show that trapped charge is approximately equal to total charge at low carrier densities in the high efficiency devices measured. Between low and high charge carrier density, the order of recombination is observed to vary from monomolecular to bimolecular to higher order. The new techniques and methods presented can be applied to any type of photovoltage device to gain insight into device operation and limitations. |
| Keywords: | organic electronics polymeric materials photovoltaic devices charge transport electronic structures electronic processes optoelectronic measurements |