Mott-Schottky Analysis of Normal and Inverted Organic Photovoltaic Devices

ORAL

Abstract

We use impedance spectroscopy to examine the electronic structure and energy band diagrams of Organic Photovoltaic (OPV) devices based on the standard donor-acceptor combination of P3HT-PCBM. Mott-Schottky analysis is performed to characterize the dark carrier densities, built-in voltages of Schottky junctions, and overall energy band diagrams in standard and inverted geometry devices with aluminum and silver top electrodes, respectively. Evidence for the decrease of dark carrier densities upon post-production thermal annealing is seen for devices in both geometries, illustrating the impact of thermal processing on the energetic band diagram. Furthermore, we find evidence for p-n junction formation at the ZnO/active layer interface in inverted devices, owing to the existence of dark carriers on both sides of the interface. We suggest that the resulting band bending at this interface helps explains the enhanced photocurrents often seen in inverted devices when compared to normal geometry devices for nominally identical active layer structures.

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Authors

  • Xin Jiang

    Dept. of Physics and Astronomy, University of Denver

  • Benjamin Bloom

    Department of Physics, University of Arizona, Tucson, AZ, National Institute for Materials Science, Tsukuba, Japan, The University of Electro-Communications, Tokyo, Langmuir Laboratory, New Mexico Tech, The University of Arizona, Brigham Young University, Department of Physics Colorado State University, Colorado School of Mines, National Renewable Energy Laboratory, University of Colorado Boulder, Principal Investigator, Graduate Student, Colorado State University, SSRL, SLAC, Department of Chemistry and Biochemistry, Brigham Young University, Department of Physics and Astronomy, Brigham Young University, National Tsing Hua University, Hsinchu, Taiwan, Colorado State Univ, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, Heinrich-Heine-Universitat, Department of Physics, University of Colorado Denver, Denver, CO 80217, Biomedical Engineering, University of Texas at Austin, Austin, TX, The University Centre in Svalbard, Utah State University, Utah Valley University, New Mexico State University, The George Washington University Nuclear Physics Research Group, Institute for Nuclear Physics at the Johannes Gutenberg University of Mainz, None, Colorado State Engineering Research Center, St. Petersburg Electrotechnical University in Saint Petersburg, Russia, University of California San Diego, Argonne National Laboratory, Los Alamos National Laboratory, Imperial College London, Space Dynamics Lab, Utah State University, Physics and CASS, Utah State University, Department of Chemistry, Colorado State University, Fort Collins, CO 80523, Department of Physics, Colorado State University, Fort Collins, CO 80523, Dept. of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Dept. of Physics and Astronomy, University of Denver, CU Boulder, RASEI, NREL, University of Colorado, Rutgers, UTK, Joint Institute for Heavy Ion Research \& ORNL, University of Guelph, Insitituto de Estructura de la Materia, University of Toronto, INFN Laboratori Nazionali del Sud, University of York, University of Surrey, TRIUMF, Simon Frasier University, Universdad de Sevilla, Simon Fraser University, Univ of Utah, Univ of Wyoming, New Mexico Tech, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, Irvine Valley College, University of Colorado - Boulder, Department of Physics, Arizona State University, Tempe, AZ, Department of Physics, New Mexico State University, Las Cruces, NM, Department of Physics, University of Michigan, Flint, MI, High Altitude Observatory, JILA, University of Colorado

  • Benjamin Bloom

    Department of Physics, University of Arizona, Tucson, AZ, National Institute for Materials Science, Tsukuba, Japan, The University of Electro-Communications, Tokyo, Langmuir Laboratory, New Mexico Tech, The University of Arizona, Brigham Young University, Department of Physics Colorado State University, Colorado School of Mines, National Renewable Energy Laboratory, University of Colorado Boulder, Principal Investigator, Graduate Student, Colorado State University, SSRL, SLAC, Department of Chemistry and Biochemistry, Brigham Young University, Department of Physics and Astronomy, Brigham Young University, National Tsing Hua University, Hsinchu, Taiwan, Colorado State Univ, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, Heinrich-Heine-Universitat, Department of Physics, University of Colorado Denver, Denver, CO 80217, Biomedical Engineering, University of Texas at Austin, Austin, TX, The University Centre in Svalbard, Utah State University, Utah Valley University, New Mexico State University, The George Washington University Nuclear Physics Research Group, Institute for Nuclear Physics at the Johannes Gutenberg University of Mainz, None, Colorado State Engineering Research Center, St. Petersburg Electrotechnical University in Saint Petersburg, Russia, University of California San Diego, Argonne National Laboratory, Los Alamos National Laboratory, Imperial College London, Space Dynamics Lab, Utah State University, Physics and CASS, Utah State University, Department of Chemistry, Colorado State University, Fort Collins, CO 80523, Department of Physics, Colorado State University, Fort Collins, CO 80523, Dept. of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Dept. of Physics and Astronomy, University of Denver, CU Boulder, RASEI, NREL, University of Colorado, Rutgers, UTK, Joint Institute for Heavy Ion Research \& ORNL, University of Guelph, Insitituto de Estructura de la Materia, University of Toronto, INFN Laboratori Nazionali del Sud, University of York, University of Surrey, TRIUMF, Simon Frasier University, Universdad de Sevilla, Simon Fraser University, Univ of Utah, Univ of Wyoming, New Mexico Tech, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, Irvine Valley College, University of Colorado - Boulder, Department of Physics, Arizona State University, Tempe, AZ, Department of Physics, New Mexico State University, Las Cruces, NM, Department of Physics, University of Michigan, Flint, MI, High Altitude Observatory, JILA, University of Colorado

  • Benjamin Bloom

    Department of Physics, University of Arizona, Tucson, AZ, National Institute for Materials Science, Tsukuba, Japan, The University of Electro-Communications, Tokyo, Langmuir Laboratory, New Mexico Tech, The University of Arizona, Brigham Young University, Department of Physics Colorado State University, Colorado School of Mines, National Renewable Energy Laboratory, University of Colorado Boulder, Principal Investigator, Graduate Student, Colorado State University, SSRL, SLAC, Department of Chemistry and Biochemistry, Brigham Young University, Department of Physics and Astronomy, Brigham Young University, National Tsing Hua University, Hsinchu, Taiwan, Colorado State Univ, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, Heinrich-Heine-Universitat, Department of Physics, University of Colorado Denver, Denver, CO 80217, Biomedical Engineering, University of Texas at Austin, Austin, TX, The University Centre in Svalbard, Utah State University, Utah Valley University, New Mexico State University, The George Washington University Nuclear Physics Research Group, Institute for Nuclear Physics at the Johannes Gutenberg University of Mainz, None, Colorado State Engineering Research Center, St. Petersburg Electrotechnical University in Saint Petersburg, Russia, University of California San Diego, Argonne National Laboratory, Los Alamos National Laboratory, Imperial College London, Space Dynamics Lab, Utah State University, Physics and CASS, Utah State University, Department of Chemistry, Colorado State University, Fort Collins, CO 80523, Department of Physics, Colorado State University, Fort Collins, CO 80523, Dept. of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Dept. of Physics and Astronomy, University of Denver, CU Boulder, RASEI, NREL, University of Colorado, Rutgers, UTK, Joint Institute for Heavy Ion Research \& ORNL, University of Guelph, Insitituto de Estructura de la Materia, University of Toronto, INFN Laboratori Nazionali del Sud, University of York, University of Surrey, TRIUMF, Simon Frasier University, Universdad de Sevilla, Simon Fraser University, Univ of Utah, Univ of Wyoming, New Mexico Tech, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, Irvine Valley College, University of Colorado - Boulder, Department of Physics, Arizona State University, Tempe, AZ, Department of Physics, New Mexico State University, Las Cruces, NM, Department of Physics, University of Michigan, Flint, MI, High Altitude Observatory, JILA, University of Colorado

  • Benjamin Bloom

    Department of Physics, University of Arizona, Tucson, AZ, National Institute for Materials Science, Tsukuba, Japan, The University of Electro-Communications, Tokyo, Langmuir Laboratory, New Mexico Tech, The University of Arizona, Brigham Young University, Department of Physics Colorado State University, Colorado School of Mines, National Renewable Energy Laboratory, University of Colorado Boulder, Principal Investigator, Graduate Student, Colorado State University, SSRL, SLAC, Department of Chemistry and Biochemistry, Brigham Young University, Department of Physics and Astronomy, Brigham Young University, National Tsing Hua University, Hsinchu, Taiwan, Colorado State Univ, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, Heinrich-Heine-Universitat, Department of Physics, University of Colorado Denver, Denver, CO 80217, Biomedical Engineering, University of Texas at Austin, Austin, TX, The University Centre in Svalbard, Utah State University, Utah Valley University, New Mexico State University, The George Washington University Nuclear Physics Research Group, Institute for Nuclear Physics at the Johannes Gutenberg University of Mainz, None, Colorado State Engineering Research Center, St. Petersburg Electrotechnical University in Saint Petersburg, Russia, University of California San Diego, Argonne National Laboratory, Los Alamos National Laboratory, Imperial College London, Space Dynamics Lab, Utah State University, Physics and CASS, Utah State University, Department of Chemistry, Colorado State University, Fort Collins, CO 80523, Department of Physics, Colorado State University, Fort Collins, CO 80523, Dept. of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Dept. of Physics and Astronomy, University of Denver, CU Boulder, RASEI, NREL, University of Colorado, Rutgers, UTK, Joint Institute for Heavy Ion Research \& ORNL, University of Guelph, Insitituto de Estructura de la Materia, University of Toronto, INFN Laboratori Nazionali del Sud, University of York, University of Surrey, TRIUMF, Simon Frasier University, Universdad de Sevilla, Simon Fraser University, Univ of Utah, Univ of Wyoming, New Mexico Tech, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, Irvine Valley College, University of Colorado - Boulder, Department of Physics, Arizona State University, Tempe, AZ, Department of Physics, New Mexico State University, Las Cruces, NM, Department of Physics, University of Michigan, Flint, MI, High Altitude Observatory, JILA, University of Colorado