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Song J, Guan Y, Wang C, Li W, Bao X, Niu L. Effect of Conductive Polymers PEDOT:PSS on Exciton Recombination and Conversion in Doped-Type BioLEDs. Polymers (Basel) 2023; 15:3275. [PMID: 37571169 PMCID: PMC10421517 DOI: 10.3390/polym15153275] [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: 07/06/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
Although the effect of the conductive polymers PEDOT:PSS on the electroluminescence performance of doped-type organic light-emitting diodes (OLEDs) has been studied, the process of PEDOT:PSS regulation of exciton recombination region and concentration within the deoxyribonucleic acid (DNA)-based doped-type BioLEDs is still obscure. In this study, we fabricated Bio-devices with and without PEDOT:PSS using varying spin-coating speeds of PEDOT:PSS. The Alq3:Rubrene-based BioLEDs achieve higher luminance (44,010 cd/m2) and higher luminance efficiency (8.1 cd/A), which are increased by 186% and 478%, respectively, compared to the reference BioLEDs without PEDOT:PSS. Similarly, the maximum luminance and efficiency of blue TCTA:TPBi exciplex-type BioLEDs are increased by 224% and 464%. In particular, our findings reveal that with an increasing thickness of PEDOT:PSS, the region of exciton recombination shifts towards the interface between the emitting layer (EML) and the hole transport layer (HTL). Meanwhile, the concentration of singlet exciton (S1,Rub) and triplet exciton (T1,Rub) increases, and the triplet-triplet annihilation (TTA) process is enhanced, resulting in the enhanced luminescence and efficiency of the devices. Accordingly, we provide a possible idea for achieving high performance doped-type BioLEDs by adding conductive polymers PEDOT:PSS, and revealing the effect of exciton recombination and conversion in BioLEDs given different PEDOT:PSS thicknesses.
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Affiliation(s)
| | - Yunxia Guan
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China; (J.S.); (C.W.); (W.L.); (X.B.)
| | | | | | | | - Lianbin Niu
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China; (J.S.); (C.W.); (W.L.); (X.B.)
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Cui H, Wang L, Ruan H, Liu M, Feng Z, Wang J, Zhao Y, Wang X. Controlling the unpaired electron by electrostatic attraction in the solid state. Chem Commun (Camb) 2021; 57:13345-13348. [PMID: 34817477 DOI: 10.1039/d1cc05244f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One-electron reduction of 2,7-tBu2-pyrene-4,5,9,10-tetraone (1) with potassium afforded two monoradicals 1K(cryp) and 1K(18c6), a radical tetramer [1K(15c5)]4 and a radical polymer (1K)2n. Using 1K(cryp) and 1K(18c6), we demonstrated large spin density modulation of an organic radical anion in the solid state by electrostatic attraction, without alternation of the molecular skeletons.
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Affiliation(s)
- Haiyan Cui
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China. .,Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Liting Wang
- Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Huapeng Ruan
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
| | - Min Liu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
| | - Zhongtao Feng
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
| | - Jie Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
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Ordon K, Merupo VI, Coste S, Noel O, Errien N, Makowska-Janusik M, Kassiba AH. Charge-transfer peculiarities in mesoporous BiVO4 surfaces with anchored indoline dyes. APPLIED NANOSCIENCE 2018. [DOI: 10.1007/s13204-018-0891-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Ji L, Haehnel M, Krummenacher I, Biegger P, Geyer FL, Tverskoy O, Schaffroth M, Han J, Dreuw A, Marder TB, Bunz UHF. Das Radikalanion und Dianion von Tetraazapentacen. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603177] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Lei Ji
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Martin Haehnel
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Ivo Krummenacher
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Philipp Biegger
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Florian L. Geyer
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Olena Tverskoy
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Manuel Schaffroth
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
| | - Jie Han
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 205 69120 Heidelberg Deutschland
| | - Andreas Dreuw
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 205 69120 Heidelberg Deutschland
| | - Todd B. Marder
- Institut für Anorganische Chemie; Julius-Maximilians-Universität Würzburg; Am Hubland 97074 Würzburg Deutschland
| | - Uwe H. F. Bunz
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Deutschland
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Ji L, Haehnel M, Krummenacher I, Biegger P, Geyer FL, Tverskoy O, Schaffroth M, Han J, Dreuw A, Marder TB, Bunz UHF. The Radical Anion and Dianion of Tetraazapentacene. Angew Chem Int Ed Engl 2016; 55:10498-501. [PMID: 27432760 DOI: 10.1002/anie.201603177] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Indexed: 11/10/2022]
Abstract
The mono- and bis-reduction of 6,13-bis((triisopropylsilyl)ethynyl)quinoxalino[2,3-b]phenazine (1) with potassium anthracenide in THF is reported. Both the radical anion 1(.-) and the dianion 1(2-) were isolated and characterized by optical and structural (single-crystal X-ray diffraction) methods. Solutions of the radical anion 1(.-) were stable in air for several hours and characterized by EPR spectroscopy. Dianion 1(2-) is highly fluorescent and photostable.
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Affiliation(s)
- Lei Ji
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Martin Haehnel
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Ivo Krummenacher
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Philipp Biegger
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Florian L Geyer
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Olena Tverskoy
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Manuel Schaffroth
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jie Han
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Andreas Dreuw
- Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Todd B Marder
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
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Organic heterojunctions: Contact-induced molecular reorientation, interface states, and charge re-distribution. Sci Rep 2016; 6:21291. [PMID: 26887445 PMCID: PMC4758050 DOI: 10.1038/srep21291] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/21/2016] [Indexed: 11/08/2022] Open
Abstract
We reveal the rather complex interplay of contact-induced re-orientation and interfacial electronic structure - in the presence of Fermi-level pinning - at prototypical molecular heterojunctions comprising copper phthalocyanine (H16CuPc) and its perfluorinated analogue (F16CuPc), by employing ultraviolet photoelectron and X-ray absorption spectroscopy. For both layer sequences, we find that Fermi-level (EF) pinning of the first layer on the conductive polymer substrate modifies the work function encountered by the second layer such that it also becomes EF-pinned, however, at the interface towards the first molecular layer. This results in a charge transfer accompanied by a sheet charge density at the organic/organic interface. While molecules in the bulk of the films exhibit upright orientation, contact formation at the heterojunction results in an interfacial bilayer with lying and co-facial orientation. This interfacial layer is not EF-pinned, but provides for an additional density of states at the interface that is not present in the bulk. With reliable knowledge of the organic heterojunction's electronic structure we can explain the poor performance of these in photovoltaic cells as well as their valuable function as charge generation layer in electronic devices.
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MacDonald GA, Veneman PA, Placencia D, Armstrong NR. Electrical property heterogeneity at transparent conductive oxide/organic semiconductor interfaces: mapping contact ohmicity using conducting-tip atomic force microscopy. ACS NANO 2012; 6:9623-9636. [PMID: 23030667 DOI: 10.1021/nn303043y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate mapping of electrical properties of heterojunctions of a molecular semiconductor (copper phthalocyanine, CuPc) and a transparent conducting oxide (indium-tin oxide, ITO), on 20-500 nm length scales, using a conductive-probe atomic force microscopy technique, scanning current spectroscopy (SCS). SCS maps are generated for CuPc/ITO heterojunctions as a function of ITO activation procedures and modification with variable chain length alkyl-phosphonic acids (PAs). We correlate differences in small length scale electrical properties with the performance of organic photovoltaic cells (OPVs) based on CuPc/C(60) heterojunctions, built on these same ITO substrates. SCS maps the "ohmicity" of ITO/CuPc heterojunctions, creating arrays of spatially resolved current-voltage (J-V) curves. Each J-V curve is fit with modified Mott-Gurney expressions, mapping a fitted exponent (γ), where deviations from γ = 2.0 suggest nonohmic behavior. ITO/CuPc/C(60)/BCP/Al OPVs built on nonactivated ITO show mainly nonohmic SCS maps and dark J-V curves with increased series resistance (R(S)), lowered fill-factors (FF), and diminished device performance, especially near the open-circuit voltage. Nearly optimal behavior is seen for OPVs built on oxygen-plasma-treated ITO contacts, which showed SCS maps comparable to heterojunctions of CuPc on clean Au. For ITO electrodes modified with PAs there is a strong correlation between PA chain length and the degree of ohmicity and uniformity of electrical response in ITO/CuPc heterojunctions. ITO electrodes modified with 6-8 carbon alkyl-PAs show uniform and nearly ohmic SCS maps, coupled with acceptable CuPc/C(60)OPV performance. ITO modified with C14 and C18 alkyl-PAs shows dramatic decreases in FF, increases in R(S), and greatly enhanced recombination losses.
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Affiliation(s)
- Gordon A MacDonald
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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Aygül U, Peisert H, Frisch J, Vollmer A, Koch N, Chassé T. Electronic Properties of Interfaces between PCPDTBT and Prototypical Electrodes Studied by Photoemission Spectroscopy. Chemphyschem 2011; 12:2345-51. [DOI: 10.1002/cphc.201000999] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 05/18/2011] [Indexed: 11/07/2022]
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Ratcliff EL, Lee PA, Armstrong NR. Work function control of hole-selective polymer/ITO anode contacts: an electrochemical doping study. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b923201j] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Armstrong NR, Veneman PA, Ratcliff E, Placencia D, Brumbach M. Oxide contacts in organic photovoltaics: characterization and control of near-surface composition in indium-tin oxide (ITO) electrodes. Acc Chem Res 2009; 42:1748-57. [PMID: 19728725 DOI: 10.1021/ar900096f] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The recent improvements in the power conversion efficiencies of organic photovoltaic devices (OPVs) promise to make these technologies increasingly attractive alternatives to more established photovoltaic technologies. OPVs typically consist of photoactive layers 20-100 nm thick sandwiched between both transparent oxide and metallic electrical contacts. Ideal OPVs rely on ohmic top and bottom contacts to harvest photogenerated charges without compromising the power conversion efficiency of the OPV. Unfortunately, the electrical contact materials (metals and metal oxides) and the active organic layers in OPVs are often incompatible and may be poorly optimized for harvesting photogenerated charges. Therefore, further optimization of the chemical and physical stabilities of these metal oxide materials with organic materials will be an essential component of the development of OPV technologies. The energetic and kinetic barriers to charge injection/collection must be minimized to maximize OPV power conversion efficiencies. In this Account, we review recent studies of one of the most common transparent conducting oxides (TCOs), indium-tin oxide (ITO), which is the transparent bottom contact in many OPV technologies. These studies of the surface chemistry and surface modification of ITO are also applicable to other TCO materials. Clean, freshly deposited ITO is intrinsically reactive toward H(2)O, CO, CO(2), etc. and is often chemically and electrically heterogeneous in the near-surface region. Conductive-tip atomic force microscopy (C-AFM) studies reveal significant spatial variability in electrical properties. We describe the use of acid activation, small-molecule chemisorption, and electrodeposition of conducting polymer films to tune the surface free energy, the effective work function, and electrochemical reactivity of ITO surfaces. Certain electrodeposited poly(thiophenes) show their own photovoltaic activity or can be used as electronically tunable substrates for other photoactive layers. For certain photoactive donor layers (phthalocyanines), we have used the polarity of the oxide surface to accelerate dewetting and "nanotexturing" of the donor layer to enhance OPV performance. These complex surface chemistries will make oxide/organic interfaces one of the key focal points for research in new OPV technologies.
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Affiliation(s)
- Neal R. Armstrong
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - P. Alex Veneman
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Erin Ratcliff
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
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Armstrong NR, Wang W, Alloway DM, Placencia D, Ratcliff E, Brumbach M. Organic/Organic′ Heterojunctions: Organic Light Emitting Diodes and Organic Photovoltaic Devices. Macromol Rapid Commun 2009; 30:717-31. [DOI: 10.1002/marc.200900075] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Accepted: 03/09/2009] [Indexed: 11/08/2022]
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Chen CP, Tien TC, Ko BT, Chen YD, Ting C. Energy level alignment at the anode of poly(3-hexylthiophene)/fullerene-based solar cells. ACS APPLIED MATERIALS & INTERFACES 2009; 1:741-745. [PMID: 20355997 DOI: 10.1021/am800259h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have used ultraviolet photoelectron spectroscopy to investigate the energy-level and band alignment near the anode for poly(3-hexylthiophene)/[6,6]-phenyl-C(61)-butyric acid methyl ester (P3HT/PCBM)-based organic solar cells. Analysis of various batches of indium-tin oxide (ITO) revealed that the photoresist residues had a strong effect, reducing the work functions of ITO (Phi(ITO)) by as much as 0.61 eV. The energy-level alignment of poly(3,4-ethylenedioxythiophene)/ITO (Phi(PEDOT/ITO)) interfaces obey the Mott-Schottky rule at values of Phi(ITO) of less than 3.92 eV. In contrast, we observed Fermi-level pinning for the blend/PEDOT interfaces at values of Phi(PEDOT/ITO) greater than 4.26 eV; this finding is consistent with a previous report that the positive polaronic energy of P3HT is equal to 4.0 eV. Consequently, we suspect that the similar efficiency levels and open-circuit voltages of devices prepared from various ITO samples were due mainly to the constant interfacial energy barrier at the blend/PEDOT interface with Fermi-level pinning.
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Li CY, Wen TC, Lee TH, Guo TF, Huang JCA, Lin YC, Hsu YJ. An inverted polymer photovoltaic cell with increased air stability obtained by employing novel hole/electron collecting layers. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b815523b] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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