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Systematic electrochemical oxidative doping of P3HT to probe interfacial charge transfer across polymer–fullerene interfaces

Journal Article · · Journal of Materials Chemistry. A
DOI:https://doi.org/10.1039/C4TA04319G· OSTI ID:1384693
 [1];  [1];  [1];  [1]
  1. Univ. of Arizona, Tucson, AZ (United States)
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This work demonstrates the detection and control of interfacial charge transfer across polymer–fullerene interfaces relevant to organic electronic platforms, including solar cells and photodetectors. Electrochemical deposition of poly(3-hexylthiophene) (e-P3HT) and subsequent electrochemical oxidation to systematically vary the fraction of oxidized thiophene (e-P3HT+) was used to form donor polymer films. The fullerene electron acceptor C60 was vacuum deposited onto the e-P3HT, and interfacial interactions were monitored with optical and photoelectron spectroscopy. Charge redistribution (sub-stoichiometric or even stoichiometric electron transfer) from e-P3HT to C60 was observed when the initial fraction of e-P3HT+ was low, as evidenced by the formation of new polaronic species and simultaneous n-doping of the C60. These charge transfer results are expected to impact interfacial rates of free carrier generation and recombination, as well as competing charge transport processes, particularly in thin film devices (<60 nm). While charge transfer of this sort has been previously observed, the ability to control the extent of charge redistribution through the systematic oxidation of the thiophene species demonstrates additional chemical tunability that can further increase the functionality of polymer–fullerene type II heterojunctions. Collectively, this work highlights the need to characterize and strategically manipulate nanoscale deviations from bulk properties in the future rational design of functional organic electronics.

Research Organization:
Energy Frontier Research Centers (EFRC) (United States). Center for Interface Science: Solar Electric Materials (CISSEM)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0001084
OSTI ID:
1384693
Alternate ID(s):
OSTI ID: 1168029
Journal Information:
Journal of Materials Chemistry. A, Journal Name: Journal of Materials Chemistry. A Journal Issue: 45 Vol. 2; ISSN JMCAET; ISSN 2050-7488
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English

References (42)

Energy Level Alignment and Interfacial Electronic Structures at Organic/Metal and Organic/Organic Interfaces journal June 1999
Intrinsic Surface Dipoles Control the Energy Levels of Conjugated Polymers journal December 2009
Electron Energetics at Surfaces and Interfaces: Concepts and Experiments journal February 2003
Formation of the Interfacial Dipole at Organic-Organic Interfaces: C60/Polymer Interfaces journal December 2007
Compensating Poly(3-hexylthiophene) Reveals Its Doping Density and Its Strong Exciton Quenching by Free Carriers journal May 2012
The influence of solid-state microstructure on the origin and yield of long-lived photogenerated charge in neat semiconducting polymers journal October 2011
Ups of buckminsterfullerene and other large clusters of carbon journal August 1987
The influence of the structural defects and microscopic aggregation of poly(3-alkylthiophenes) on electrochemical and optical properties of the polymer films: discussion of an origin of redox peaks in the cyclic voltammograms journal August 2001
Photoemission studies of functional organic materials and their interfaces journal March 1998
Doping-induced realignment of molecular levels at organic–organic heterojunctions journal June 2006
Energy level alignment regimes at hybrid organic–organic and inorganic–organic interfaces journal February 2007
Direct determination of the electronic structure of the poly(3-hexylthiophene):phenyl-[6,6]-C61 butyric acid methyl ester blend journal November 2010
Chemically Treating Poly(3-hexylthiophene) Defects to Improve Bulk Heterojunction Photovoltaics journal May 2011
Deciphering the Metal-C 60 Interface in Optoelectronic Devices: Evidence for C 60 Reduction by Vapor Deposited Al journal June 2013
Molecular Understanding of Organic Solar Cells: The Challenges journal November 2009
Electrodeposited, “Textured” Poly(3-hexyl-thiophene) (e-P3HT) Films for Photovoltaic Applications journal September 2008
Charge Photogeneration in Organic Solar Cells journal November 2010
Photoinduced Charge Generation and Recombination Dynamics in Model Donor/Acceptor Pairs for Organic Solar Cell Applications:  A Full Quantum-Chemical Treatment journal April 2005
Charge Carrier Formation in Polythiophene/Fullerene Blend Films Studied by Transient Absorption Spectroscopy journal March 2008
Multiple Exciton Dissociation in CdSe Quantum Dots by Ultrafast Electron Transfer to Adsorbed Methylene Blue journal April 2010
On the Origin of the So-Called Nucleation Loop during Electropolymerization of Conducting Polymers journal February 2007
Exciton Dissociation at Thiophene/Fullerene Interfaces: The Electronic Structures and Quantum Dynamics journal April 2011
Relation between Microstructure and Charge Transport in Polymers of Different Regioregularity journal September 2011
Quantum-Chemical Approach to Electronic Coupling:  Application to Charge Separation and Charge Recombination Pathways in a Model Molecular Donor−Acceptor System for Organic Solar Cells journal March 2008
Reappraising the Need for Bulk Heterojunctions in Polymer−Fullerene Photovoltaics: The Role of Carrier Transport in All-Solution-Processed P3HT/PCBM Bilayer Solar Cells journal October 2009
Selective Interlayers and Contacts in Organic Photovoltaic Cells journal May 2011
Quantitative Transient Absorption Measurements of Polaron Yield and Absorption Coefficient in Neat Conjugated Polymers journal June 2013
Spectroelectrochemical and AFM Studies of Doping−Undoping of Poly(3-hexylthiophene) Films in Propylene Carbonate and Aqueous Solutions of LiClO 4 journal March 2003
Modification of Indium−Tin Oxide Electrodes with Thiophene Copolymer Thin Films:  Optimizing Electron Transfer to Solution Probe Molecules journal January 2007
Surface Composition and Electrical and Electrochemical Properties of Freshly Deposited and Acid-Etched Indium Tin Oxide Electrodes journal October 2007
Molecular control of luminescence from poly(3-hexylthiophenes) journal August 1993
Insights on Interfacial Charge Transfer Across P3HT/Fullerene Photovoltaic Heterojunction from Ab Initio Calculations journal July 2007
Photocatalysis with CdSe Nanoparticles in Confined Media: Mapping Charge Transfer Events in the Subpicosecond to Second Timescales journal February 2009
A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene:fullerene solar cells journal February 2006
Charge separation energetics at organic heterojunctions: on the role of structural and electrostatic disorder journal January 2014
Work function control of hole-selective polymer/ITO anode contacts: an electrochemical doping study journal January 2010
Structural variability and dynamics of the P3HT/PCBM interface and its effects on the electronic structure and the charge-transfer rates in solar cells journal January 2011
Electronic structure of the poly(3-hexylthiophene):indene-C 60 bisadduct bulk heterojunction journal August 2011
Charge transfer, doping, and interface morphologies for Al- C 60 journal June 1995
Ultrafast spectroscopic investigation of a fullerene poly(3-hexylthiophene) dyad journal August 2011
Role of band states and trap states in the electrical properties of organic semiconductors: Hopping versus mobility edge model journal May 2013
Charge Separation in Semicrystalline Polymeric Semiconductors by Photoexcitation: Is the Mechanism Intrinsic or Extrinsic? journal May 2011

Cited By (3)

Tuning charge transport dynamics via clustering of doping in organic semiconductor thin films journal July 2019
Neutron Radiation Tolerance of Two Benchmark Thiophene-Based Conjugated Polymers: the Importance of Crystallinity for Organic Avionics journal January 2017
Synthesis and characterization of poly(3-hexylthiophene): improvement of regioregularity and energy band gap journal January 2018

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Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
charge transport
electrodes - solar
solar (photovoltaic)
synthesis (novel materials)
synthesis (scalable processing)
synthesis (self-assembly)