1
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Bothra U, Venugopal H, Kabra D, McNeill CR, Liu ACY. Visualization of Nanocrystallites in Organic Semiconducting Blends Using Cryo-Electron Microscopy. SMALL METHODS 2024; 8:e2301352. [PMID: 38349044 DOI: 10.1002/smtd.202301352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/19/2024] [Indexed: 08/18/2024]
Abstract
The efficiency of an organic solar cell is highly dependent on the complex, interpenetrating morphology, and molecular order within the composite phases of the bulk heterojunction (BHJ) blend. Both these microstructural aspects are strongly influenced by the processing conditions and chemical design of donor/acceptor materials. To establish improved structure-function relationships, it is vital to visualize the local microstructural order to provide specific local information about donor/acceptor interfaces and crystalline texture in BHJ blend films. The visualization of nanocrystallites, however, is difficult due to the complex semi-crystalline structure with few characterization techniques capable of visualizing the molecular ordering of soft materials at the nanoscale. Here, it is demonstrated how cryo-electron microscopy can be utilized to visualize local nanoscale order. This method is used to understand the distribution/orientation of crystallites in a BHJ blend. Long-range (>300 nm) texturing of IEICO-4F crystallites oriented in an edge-on fashion is observed, which has not previously been observed for spin-coated materials. This approach provides a wealth of quantitative information about the texture and size of nanocrystallites, which can be utilized to understand charge generation and transport in organic film. This study guides tailoring the material design and processing conditions for high-performance organic optoelectronic devices.
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Affiliation(s)
- Urvashi Bothra
- IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai, 400076, India
- Department of Physics, IIT Bombay, Powai, Mumbai, 400076, India
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Hariprasad Venugopal
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Victoria, 3800, Australia
| | - Dinesh Kabra
- Department of Physics, IIT Bombay, Powai, Mumbai, 400076, India
| | - Christopher R McNeill
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Amelia C Y Liu
- School of Physics and Astronomy, Monash University, Clayton, Victoria, 3800, Australia
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2
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Jungbluth A, Cho E, Privitera A, Yallum KM, Kaienburg P, Lauritzen AE, Derrien T, Kesava SV, Habib I, Pratik SM, Banerji N, Brédas JL, Coropceanu V, Riede M. Limiting factors for charge generation in low-offset fullerene-based organic solar cells. Nat Commun 2024; 15:5488. [PMID: 38942793 PMCID: PMC11213929 DOI: 10.1038/s41467-024-49432-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 06/05/2024] [Indexed: 06/30/2024] Open
Abstract
Free charge generation after photoexcitation of donor or acceptor molecules in organic solar cells generally proceeds via (1) formation of charge transfer states and (2) their dissociation into charge separated states. Research often either focuses on the first component or the combined effect of both processes. Here, we provide evidence that charge transfer state dissociation rather than formation presents a major bottleneck for free charge generation in fullerene-based blends with low energetic offsets between singlet and charge transfer states. We investigate devices based on dilute donor content blends of (fluorinated) ZnPc:C60 and perform density functional theory calculations, device characterization, transient absorption spectroscopy and time-resolved electron paramagnetic resonance measurements. We draw a comprehensive picture of how energies and transitions between singlet, charge transfer, and charge separated states change upon ZnPc fluorination. We find that a significant reduction in photocurrent can be attributed to increasingly inefficient charge transfer state dissociation. With this, our work highlights potential reasons why low offset fullerene systems do not show the high performance of non-fullerene acceptors.
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Affiliation(s)
- Anna Jungbluth
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Eunkyung Cho
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
- Division of Energy Technology, DGIST, Daegu, 42988, Republic of Korea
| | - Alberto Privitera
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
- Department of Industrial Engineering and INSTM Research Unit, University of Florence, 50139, Firenze, Italy
| | - Kaila M Yallum
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012, Bern, Switzerland
| | - Pascal Kaienburg
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Andreas E Lauritzen
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Thomas Derrien
- Diamond Light Source, Didcot, Oxfordshire, OX11 0DE, UK
- Living Systems Institute, University of Exeter, Exeter, EX4 4QD, UK
| | - Sameer V Kesava
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Irfan Habib
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Saied Md Pratik
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Natalie Banerji
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012, Bern, Switzerland
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Veaceslav Coropceanu
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Moritz Riede
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK.
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3
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McAnally S, Jin H, Chu R, Mallo N, Wang X, Burn PL, Gentle IR, Shaw PE. Dilute Donor Organic Solar Cells Based on Non-fullerene Acceptors. ACS APPLIED MATERIALS & INTERFACES 2024; 16:28958-28968. [PMID: 38787283 DOI: 10.1021/acsami.4c02864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
The advent of small molecule non-fullerene acceptor (NFA) materials for organic photovoltaic (OPV) devices has led to a series of breakthroughs in performance and device lifetime. The most efficient OPV devices have a combination of electron donor and acceptor materials that constitute the light absorbing layer in a bulk heterojunction (BHJ) structure. For many BHJ-based devices reported to date, the weight ratio of donor to acceptor is near equal. However, the morphology of such films can be difficult to reproduce and manufacture at scale. There would be an advantage in developing a light harvesting layer for efficient OPV devices that contains only a small amount of either the donor or acceptor. In this work we explore low donor content OPV devices composed of the polymeric donor PM6 blended with high performance NFA materials, Y6 or ITIC-4F. We found that even when the donor:acceptor weight ratio was only 1:10, the OPV devices still have good photoconversion efficiencies of around 6% and 5% for Y6 and ITIC-4F, respectively. It was found that neither charge mobility nor recombination rates had a strong effect on the efficiency of the devices. Rather, the overall efficiency was strongly related to the film absorption coefficient and maintaining adequate interfacial surface area between donor and acceptor molecules/phases for efficient exciton dissociation.
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Affiliation(s)
- Shaun McAnally
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Hui Jin
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ronan Chu
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Neil Mallo
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiao Wang
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul L Burn
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ian R Gentle
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul E Shaw
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
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4
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Stroet M, Sanderson S, Sanzogni AV, Nada S, Lee T, Caron B, Mark AE, Burn PL. PyThinFilm: Automated Molecular Dynamics Simulation Protocols for the Generation of Thin Film Morphologies. J Chem Inf Model 2023; 63:2-8. [PMID: 36539938 DOI: 10.1021/acs.jcim.2c01334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The performance of organic optoelectronic devices, such as organic light-emitting diodes (OLEDs) and organic solar cells (OSCs), is intrinsically related to the molecular-scale morphology of the thin films from which they are composed. However, the experimental characterization of morphology at the molecular level is challenging due to the often amorphous or at best semicrystalline nature of these films. Classical molecular modeling techniques, such as molecular dynamics (MD) simulation, are increasingly used to understand the relationship between morphology and the properties of thin-film devices. PyThinFilm (github.com/ATB-UQ/PyThinFilm) is an open-source Python package which allows fully automated MD simulations of thin film growth to be performed using vacuum and/or solution deposition processes. PyThinFilm utilizes the GROMACS simulation package in combination with interaction parameters from the Automated Topology Builder (atb.uq.edu.au). Here, PyThinFilm is described along with an overview of applications in which PyThinFilm has been used to study the thin films of organic semiconductor materials typically used in OLEDs and OSCs.
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Affiliation(s)
- Martin Stroet
- Centre for Organic Photonics & Electronics, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia.,Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Stephen Sanderson
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia.,College of Science and Engineering, James Cook University, Townsville, Queensland4811, Australia
| | - Audrey V Sanzogni
- Centre for Organic Photonics & Electronics, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia.,Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Sharif Nada
- Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Thomas Lee
- Centre for Organic Photonics & Electronics, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia.,Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Bertrand Caron
- Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Alan E Mark
- Molecular Dynamics Group, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
| | - Paul L Burn
- Centre for Organic Photonics & Electronics, The University of Queensland, St Lucia Campus, Brisbane, Queensland4072, Australia
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5
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Studying the Effect of High Substrate Temperature on the Microstructure of Vacuum Evaporated TAPC: C 60 Organic Solar Thin Films. MATERIALS 2021; 14:ma14071733. [PMID: 33916107 PMCID: PMC8037502 DOI: 10.3390/ma14071733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/23/2022]
Abstract
Organic solar cells (OSCs), also known as organic photovoltaics (OPVs), are an emerging solar cell technology composed of carbon-based, organic molecules, which convert energy from the sun into electricity. Key for their performance is the microstructure of the light-absorbing organic bulk heterojunction. To study this, organic solar films composed of both fullerene C60 as electron acceptor and different mole percentages of di-[4-(N,N-di-p-tolyl-amino)-phenyl]-cyclohexane (TAPC) as electron donor were evaporated in vacuum in different mixing ratios (5, 50 and 95 mol%) on an ITO-coated glass substrate held at room temperature and at 110 °C. The microstructure of the C60: TAPC heterojunction was studied by grazing incidence wide angle X-ray scattering to understand the effect of substrate heating. By increasing the substrate temperature from ambient to 110 °C, it was found that no significant change was observed in the crystal size for the C60: TAPC concentrations investigated in this study. In addition to the variation done in the substrate temperature, the variation of the mole percent of the donor (TAPC) was studied to conclude the effect of both the substrate temperature and the donor concentration on the microstructure of the OSC films. Bragg peaks were attributed to C60 in the pure C60 sample and in the blend with low donor mole percentage (5%), but the C60 peaks became nondiscernible when the donor mole percentage was increased to 50% and above, showing that TAPC interrupted the formation of C60 crystals.
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6
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Londi G, Khan SUZ, Muccioli L, D'Avino G, Rand BP, Beljonne D. Fate of Low-Lying Charge-Transfer Excited States in a Donor:Acceptor Blend with a Large Energy Offset. J Phys Chem Lett 2020; 11:10219-10226. [PMID: 33206537 DOI: 10.1021/acs.jpclett.0c02858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In an effort to gain a comprehensive picture of the interfacial states in bulk heterojunction solar cells, we provide a combined experimental-theoretical analysis of the energetics and dynamics of low-lying electronic charge-transfer (CT) states in donor:acceptor blends with a large frontier orbital energy offset. By varying the blend composition and temperature, we unravel the static and dynamic contributions to the disordered density of states (DOS) of the CT-state manifold and assess their recombination to the ground state. Namely, we find that static disorder (conformational and electrostatic) shapes the CT DOS and that fast nonradiative recombination crops the low-energy tail of the distribution probed by external quantum efficiency (EQE) measurements (thereby largely contributing to voltage losses). Our results then question the standard practice of extracting microscopic parameters such as exciton energy and energetic disorder from EQE.
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Affiliation(s)
- Giacomo Londi
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Saeed-Uz-Zaman Khan
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Luca Muccioli
- Department of Industrial Chemistry, University of Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
| | - Gabriele D'Avino
- Grenoble Alpes University, CNRS, Grenoble INP, Institut Néel, 25 rue des Martyrs, 38042 Grenoble, France
| | - Barry P Rand
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, United States
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, 7000 Mons, Belgium
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7
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Boittier ED, Burns JM, Gandhi NS, Ferro V. GlycoTorch Vina: Docking Designed and Tested for Glycosaminoglycans. J Chem Inf Model 2020; 60:6328-6343. [PMID: 33152249 DOI: 10.1021/acs.jcim.0c00373] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glycosaminoglycans (GAGs) are a family of anionic carbohydrates that play an essential role in the physiology and pathology of all eukaryotic life forms. Experimental determination of GAG-protein complexes is challenging due to their difficult isolation from biological sources, natural heterogeneity, and conformational flexibility-including possible ring puckering of sulfated iduronic acid from 1C4 to 2SO conformation. To overcome these challenges, we present GlycoTorch Vina (GTV), a molecular docking tool based on the carbohydrate docking program VinaCarb (VC). Our program is unique in that it contains parameters to model 2SO sugars while also supporting glycosidic linkages specific to GAGs. We discuss how crystallographic models of carbohydrates can be biased by the choice of refinement software and structural dictionaries. To overcome these variations, we carefully curated 12 of the best available GAG and GAG-like crystal structures (ranging from tetra- to octasaccharides or longer) obtained from the PDB-REDO server and refined using the same protocol. Both GTV and VC produced pose predictions with a mean root-mean-square deviation (RMSD) of 3.1 Å from the native crystal structure-a statistically significant improvement when compared to AutoDock Vina (4.5 Å) and the commercial software Glide (5.9 Å). Examples of how real-space correlation coefficients can be used to better assess the accuracy of docking pose predictions are given. Comparisons between statistical distributions of empirical "salt bridge" interactions, relevant to GAGs, were compared to density functional theory (DFT) studies of model salt bridges, and water-mediated salt bridges; however, there was generally a poor agreement between these data. Water bridges appear to play an important, yet poorly understood, role in the structures of GAG-protein complexes. To aid in the rapid prototyping of future pose scoring functions, we include a module that allows users to include their own torsional and nonbonded parameters.
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Affiliation(s)
- Eric D Boittier
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jed M Burns
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Neha S Gandhi
- Chemistry and Physics, Centre for Genomics and Personalised Health, Faculty of Science and Engineering, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Vito Ferro
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
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8
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Lee T, Sanzogni AV, Burn PL, Mark AE. Evolution and Morphology of Thin Films Formed by Solvent Evaporation: An Organic Semiconductor Case Study. ACS APPLIED MATERIALS & INTERFACES 2020; 12:40548-40557. [PMID: 32844643 DOI: 10.1021/acsami.0c08454] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The crucial role played by the solution-vapor interface in determining the growth and morphology of an organic semiconductor thin film formed by solvent evaporation has been examined in atomic detail. Specifically, how the loss of individual solvent molecules from the surface of the solution induces solute assembly has been studied using molecular dynamics simulations. The system consisted of bis(2-phenylpyridine) (acetylacetonate)iridium(III) [Ir(ppy)2(acac)] and 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) in chloroform at 310 K. The simulations clearly indicate that (a) the system does not undergo uniform phase separation (spinodal decomposition), (b) solute aggregation initiates at the solution-vapor interface, (c) the distribution of solvent in the film is nonhomogeneous, (d) this nonhomogeneous distribution can induce preferential alignment of host molecules, and (e) a portion of the solvent likely remains trapped within the film. The work not only demonstrates the ability to directly model evaporation in atomic detail on the relevant length scales but also shows that atomistic simulations have the potential to shed new light on morphological properties of a wide range of organic semiconductor devices manufactured using solution-processing methods.
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Affiliation(s)
- Thomas Lee
- School of Chemistry & Molecular Biosciences, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
- Centre for Organic Photonics & Electronics, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
| | - Audrey V Sanzogni
- School of Chemistry & Molecular Biosciences, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
- Centre for Organic Photonics & Electronics, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
| | - Paul L Burn
- School of Chemistry & Molecular Biosciences, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
- Centre for Organic Photonics & Electronics, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
| | - Alan E Mark
- School of Chemistry & Molecular Biosciences, The University of Queensland, St. Lucia Campus, Brisbane 4072, Australia
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9
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Moore GJ, Causa' M, Martinez Hardigree JF, Karuthedath S, Ramirez I, Jungbluth A, Laquai F, Riede M, Banerji N. Ultrafast Charge Dynamics in Dilute-Donor versus Highly Intermixed TAPC:C 60 Organic Solar Cell Blends. J Phys Chem Lett 2020; 11:5610-5617. [PMID: 32564605 DOI: 10.1021/acs.jpclett.0c01495] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Elucidating the interplay between film morphology, photophysics, and device performance of bulk heterojunction (BHJ) organic photovoltaics remains challenging. Here, we use the well-defined morphology of vapor-deposited di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC):C60 blends to address charge generation and recombination by transient ultrafast spectroscopy. We gain relevant new insights to the functioning of dilute-donor (5% TAPC) fullerene-based BHJs compared to molecularly intermixed systems (50% TAPC). First, we show that intermolecular charge-transfer (CT) excitons in the C60 clusters of dilute BHJs rapidly localize to Frenkel excitons prior to dissociating at the donor:acceptor interface. Thus, both Frenkel and CT excitons generate photocurrent over the entire fullerene absorption range. Second, we selectively monitor interfacial and bulk C60 clusters via their electro-absorption, demonstrating an energetic gradient that assists free charge generation. Third, we identify a fast (<1 ns) recombination channel, whereby free electrons recombine with trapped holes on isolated TAPC molecules. This can harm the performance of dilute solar cells, unless the electrons are rapidly extracted in efficient devices.
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Affiliation(s)
- Gareth John Moore
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Martina Causa'
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | | | - Safakath Karuthedath
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Ivan Ramirez
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU Oxford, U.K
| | - Anna Jungbluth
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU Oxford, U.K
| | - Frédéric Laquai
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Moritz Riede
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU Oxford, U.K
| | - Natalie Banerji
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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10
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Yu J, Phang P, Samundsett C, Basnet R, Neupan GP, Yang X, Macdonald DH, Wan Y, Yan D, Ye J. Titanium Nitride Electron-Conductive Contact for Silicon Solar Cells By Radio Frequency Sputtering from a TiN Target. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26177-26183. [PMID: 32402191 DOI: 10.1021/acsami.0c04439] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Efficient and stable electron selective materials compatible with commercial production are essential to the fabrication of dopant-free silicon solar cells. In this work, we report an air-stable TiN (titanium nitride) polycrystalline film, deposited using radio frequency sputtering process, as an electron selective contact in silicon solar cells. TiN films deposited at 300 W and 1.5 mTorr exhibit a low contact resistivity of 2.0 mΩ·cm2. Furthermore, the main factors and mechanisms affecting the carrier selectivity properties are also explored. TiN layers as full area rear electron contacts in n-type silicon solar cells have been successfully implemented, even though TiN film contains some oxygen. This process yields a 17% increment in relative efficiency in comparison with reference devices (n-Si/Al contact). Hence, considering the low thermal budget, scalable technique, and low contact resistivity, the TiN layers can pave the way to fabricate high-efficiency selective contact silicon solar cells with a higher degree of reproducibility.
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Affiliation(s)
- Jing Yu
- Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences (CAS), Ningbo City 315201, P. R. China
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
- University of Chinese Academy of Sciences, Beijing City 100049, P. R. China
| | - Pheng Phang
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Christian Samundsett
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Rabin Basnet
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Guru P Neupan
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Xi Yang
- Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences (CAS), Ningbo City 315201, P. R. China
| | - Daniel H Macdonald
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Yimao Wan
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Di Yan
- Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2601, Australia
| | - Jichun Ye
- Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences (CAS), Ningbo City 315201, P. R. China
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11
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Jiang W, Stolterfoht M, Jin H, Burn PL. Hole-Transporting Poly(dendrimer)s as Electron Donors for Low Donor Organic Solar Cells with Efficient Charge Transport. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wei Jiang
- Centre for Organic Photonics & Electronics (COPE), School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Martin Stolterfoht
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - Hui Jin
- Centre for Organic Photonics & Electronics (COPE), School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Paul L. Burn
- Centre for Organic Photonics & Electronics (COPE), School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia QLD 4072, Australia
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12
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Li P, Chan CY, Lai SL, Chan H, Leung MY, Hong EYH, Li J, Wu H, Chan MY, Yam VWW. Three-Dimensional Spirothienoquinoline-Based Small Molecules for Organic Photovoltaic and Organic Resistive Memory Applications. ACS APPLIED MATERIALS & INTERFACES 2020; 12:11865-11875. [PMID: 32115950 DOI: 10.1021/acsami.9b19746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A new electron-rich spirothienoquinoline unit, tBuSAF-Th, has been developed via incorporation of a thienyl unit instead of a phenyl unit into the six-membered ring of the spiroacridine (SAF) and utilized for the first time as a building block for constructing small-molecule electron donors in organic solar cells (OSCs) and as active layers in organic resistive memory devices. The resulting three-dimensional spirothienoquinoline-containing 1-4 exhibit high-lying highest occupied molecular orbital (HOMO) energy levels. By the introduction of electron-deficient benzochalcogenodiazole linkers, with the chalcogen atoms being varied from O to S and Se, a progressively lower lowest unoccupied molecular orbital (LUMO) energy level has been achieved while keeping the HOMO energy levels similar. This strategy has allowed an enhanced light-harvesting ability without compromising open-circuit voltage (Voc) in vacuum-deposited bulk heterojunction OSCs using 1-4 as donors and C70 as the acceptor. Good photovoltaic performances with power conversion efficiencies (PCEs) of up to 3.86% and high short-circuit current densities (Jsc) of up to 10.84 mA cm-2 have been achieved. In addition, organic resistive memory devices fabricated with these donor-acceptor small molecules exhibit binary logic memory behaviors with long retention times and high on/off current ratios. This work indicates that the spirothienoquinoline moiety is a potential building block for constructing multifunctional organic electronic materials.
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Affiliation(s)
- Panpan Li
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Chin-Yiu Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Hing Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Ming-Yi Leung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Eugene Yau-Hin Hong
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Jingwen Li
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
| | - Hongbin Wu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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