Correlated In Situ Low‐Frequency Noise and Impedance Spectroscopy Reveal Recombination Dynamics in Organic Solar Cells Using Fullerene and Non‐Fullerene Acceptors
Year: 2017
Type: article
Abstract: Non‐fullerene acceptors based on perylenediimides (PDIs) have garnered significant interest as an alternative to fullerene acceptors in organic photovoltaics (OPVs), but their charge transport phenomena are not well understood, especially in bulk heterojunctions (BHJs). Here, charge transport and current fluctuations are investigated by performing correlated low‐frequency noise and impedance spectroscopy measurements on two BHJ OPV systems, one employing a fullerene acceptor and the other employing a dimeric PDI acceptor. In the dark, these measurements reveal that PDI‐based OPVs have a greater degree of recombination in comparison to fullerene‐based OPVs. Furthermore, for the first time in organic solar cells, 1/f noise data are fit to the Kleinpenning model to reveal underlying current fluctuations in different transport regimes. Under illumination, 1/f noise increases by approximately four orders of magnitude for the fullerene‐based OPVs and three orders of magnitude for the PDI‐based OPVs. An inverse correlation is also observed between noise spectral density and power conversion efficiency. Overall, these results show that low‐frequency noise spectroscopy is an effective in situ diagnostic tool to assess charge transport in emerging photovoltaic materials, thereby providing quantitative guidance for the design of next‐generation solar cell materials and technologies.
Source: Advanced Functional Materials
Institution: Northwestern University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, W. M. Keck Foundation, Northwestern University, Office of Science, Materials Research Science and Engineering Center, Harvard University, International Institute for Nanotechnology, Northwestern University, Division of Materials Research, Basic Energy Sciences, Argonne National Laboratory
Awards: G1794054907, G1908987099, G2379832748, POWER MANAGEMENT HAS EMERGED AS A CRITICAL ISSUE THAT IS THREATENING CONTINUED SCALING IN HIGH-PERFORMANCE COMPLEMENTARY METAL-OXIDE-SEMICONDUCTOR (C, G2491707747, G318734614, G4573007502, G5335290279, NNCI: Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource, G6066762027, G7178204, ARGONNE-NORTHWESTERN SOLAR ENERGY RESEARCH (ANSER) CENTER -- EFRC, G7241967701, CEMRI: Multifunctional Nanoscale Material Structures, G8172060556, ARGONNE-NORTHWESTERN SOLAR ENERGY RESEARCH (ANSER) CENTER -- EFRC
OpenAlex ID: W2759434059