1
|
Mohapatra AA, Pranav M, Yadav S, Gangadharappa C, Wu J, Labanti C, Wolansky J, Benduhn J, Kim JS, Durrant J, Patil S. Interface Engineering in Perylene Diimide-Based Organic Photovoltaics with Enhanced Photovoltage. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37191283 DOI: 10.1021/acsami.3c02003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The introduction of nonfullerene acceptors (NFA) facilitated the realization of high-efficiency organic solar cells (OSCs); however, OSCs suffer from relatively large losses in open-circuit voltage (VOC) as compared to inorganic or perovskite solar cells. Further enhancement in power conversion efficiency requires an increase in VOC. In this work, we take advantage of the high dipole moment of twisted perylene-diimide (TPDI) as a nonfullerene acceptor (NFA) to enhance the VOC of OSCs. In multiple bulk heterojunction solar cells incorporating TPDI with three polymer donors (PTB7-Th, PM6 and PBDB-T), we observed a VOC enhancement by modifying the cathode with a polyethylenimine (PEIE) interlayer. We show that the dipolar interaction between the TPDI NFA and PEIE─enhanced by the general tendency of TPDI to form J-aggregates─plays a crucial role in reducing nonradiative voltage losses under a constant radiative limit of VOC. This is aided by comparative studies with PM6:Y6 bulk heterojunction solar cells. We hypothesize that incorporating NFAs with significant dipole moments is a feasible approach to improving the VOC of OSCs.
Collapse
Affiliation(s)
| | - Manasi Pranav
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Suraj Yadav
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | | | - Jiaying Wu
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - Chiara Labanti
- Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jakob Wolansky
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute of Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany
| | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute of Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany
| | - Ji-Seon Kim
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
| | - James Durrant
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, United Kingdom
- SPECIFIC IKC, College of Engineering, Swansea University, Bay Campus, Swansea, Wales SA1 8EN, United Kingdom
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
2
|
Pranav M, Benduhn J, Nyman M, Hosseini SM, Kublitski J, Shoaee S, Neher D, Leo K, Spoltore D. Enhanced Charge Selectivity via Anodic-C 60 Layer Reduces Nonradiative Losses in Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:12603-12609. [PMID: 33660501 DOI: 10.1021/acsami.1c00049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Interfacial layers in conjunction with suitable charge-transport layers can significantly improve the performance of optoelectronic devices by facilitating efficient charge carrier injection and extraction. This work uses a neat C60 interlayer on the anode to experimentally reveal that surface recombination is a significant contributor to nonradiative recombination losses in organic solar cells. These losses are shown to proportionally increase with the extent of contact between donor molecules in the photoactive layer and a molybdenum oxide (MoO3) hole extraction layer, proven by calculating voltage losses in low- and high-donor-content bulk heterojunction device architectures. Using a novel in-device determination of the built-in voltage, the suppression of surface recombination, due to the insertion of a thin anodic-C60 interlayer on MoO3, is attributed to an enhanced built-in potential. The increased built-in voltage reduces the presence of minority charge carriers at the electrodes-a new perspective on the principle of selective charge extraction layers. The benefit to device efficiency is limited by a critical interlayer thickness, which depends on the donor material in bilayer devices. Given the high popularity of MoO3 as an efficient hole extraction and injection layer and the increasingly popular discussion on interfacial phenomena in organic optoelectronic devices, these findings are relevant to and address different branches of organic electronics, providing insights for future device design.
Collapse
Affiliation(s)
- Manasi Pranav
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187 Dresden, Germany
| | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187 Dresden, Germany
| | - Mathias Nyman
- Faculty of Science and Engineering, Åbo Akademi University, Porthansgatan 3, 20500 Turku, Finland
| | - Seyed Mehrdad Hosseini
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Jonas Kublitski
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187 Dresden, Germany
| | - Safa Shoaee
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Dieter Neher
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Karl Leo
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187 Dresden, Germany
| | - Donato Spoltore
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Straße 61, 01187 Dresden, Germany
| |
Collapse
|
3
|
Ramirez I, Privitera A, Karuthedath S, Jungbluth A, Benduhn J, Sperlich A, Spoltore D, Vandewal K, Laquai F, Riede M. The role of spin in the degradation of organic photovoltaics. Nat Commun 2021; 12:471. [PMID: 33473110 PMCID: PMC7817674 DOI: 10.1038/s41467-020-20601-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 12/07/2020] [Indexed: 11/09/2022] Open
Abstract
Stability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.
Collapse
Affiliation(s)
- Ivan Ramirez
- Heliatek GmbH, Treidlerstrasse 3, 01139, Dresden, Germany.
| | - Alberto Privitera
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU, Oxford, UK
| | - Safakath Karuthedath
- KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), 23955-6900, Thuwai, Saudi Arabia
| | - Anna Jungbluth
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU, Oxford, UK
| | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Andreas Sperlich
- Experimental Physics 6, Julius Maximilian University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Donato Spoltore
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Strasse 61, 01187, Dresden, Germany
| | - Koen Vandewal
- Institute for Materials Research (IMO-IMOMEC), Hasselt University, Wetenschapspark 1, 3590, Diepenbeek, Belgium
| | - Frédéric Laquai
- KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), 23955-6900, Thuwai, Saudi Arabia
| | - Moritz Riede
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU, Oxford, UK.
| |
Collapse
|
4
|
Sandberg OJ, Zeiske S, Zarrabi N, Meredith P, Armin A. Charge Carrier Transport and Generation via Trap-Mediated Optical Release in Organic Semiconductor Devices. PHYSICAL REVIEW LETTERS 2020; 124:128001. [PMID: 32281832 DOI: 10.1103/physrevlett.124.128001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/13/2020] [Accepted: 03/03/2020] [Indexed: 06/11/2023]
Abstract
The impact of intermixed donor-acceptor domains in organic bulk heterojunction (BHJ) solar cells, using low-donor-content devices as model systems, is clarified. At low donor contents, the devices are found to exhibit anomalously high open-circuit voltages independent of the donor-acceptor energetics. These observations can be consistently explained by a theoretical model based on optical release of trapped holes, assuming the donors behave as trap sites in the gap of the acceptor. Our findings provide guidelines for reducing the large open-circuit voltage losses in organic solar cells and avoiding morphology-induced losses in state-of-the-art BHJ solar cells and photodetectors.
Collapse
Affiliation(s)
- Oskar J Sandberg
- Sustainable Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP Wales, United Kingdom
| | - Stefan Zeiske
- Sustainable Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP Wales, United Kingdom
| | - Nasim Zarrabi
- Sustainable Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP Wales, United Kingdom
| | - Paul Meredith
- Sustainable Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP Wales, United Kingdom
| | - Ardalan Armin
- Sustainable Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP Wales, United Kingdom
| |
Collapse
|