Structural Nanoprobes of Organic Semiconductor Devices
Lead Research Organisation:
University of Cambridge
Department Name: Physics
Abstract
Organic semiconductors are an exciting new class of material that combine the electronic properties traditionally only associated with inorganic materials, with the mechanical properties and processibility of polymers (plastics) and small organic molecules. In particular, the ability to process active semiconductor layers through solution processing has led to the commercialisation of organic light-emitting diode-based displays. Commercial potential has also been demonstrated by organic transistors and organic solar cells, where both technologies have the advantage of low-cost processing and the ability to be incorporated into flexible architectures.However, as organic semiconductors are a relatively new class of material, there are still many fundamental questions governing key processes that affect device performance. For example, organic semiconductor films are typically less ordered than their inorganic counterparts and the influence of domain structure, molecular orientation and molecular alignment on charge transport is not fully understood. Additionally, for organic solar cells, where typically two different materials are blended together to form efficient networks for charge separation and transport, the influence of material mixing on charge separation and transport are still being discovered.Since organic semiconductors have vastly different properties compared to inorganic semiconductors, the development and application of new techniques to probe the properties of this new class of material is required. This research programme will adapt state-of-the-art microscopes and utilize advanced X-ray analytical techniques to probe structure and device action in organic devices with unprecedented precision and clarity. This further understanding of device operation will allow for the identification of physical processes that limit device performance and hence promote future device optimisation.
Publications
Marsh RA
(2008)
A unified description of current-voltage characteristics in organic and hybrid photovoltaics under low light intensity.
in Nano letters
Collins B
(2012)
Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in PTB7:PC 71 BM Solar Cells
in Advanced Energy Materials
Oosterbaan W
(2010)
Alkyl-Chain-Length-Independent Hole Mobility via Morphological Control with Poly(3-alkylthiophene) Nanofibers
in Advanced Functional Materials
McNeill C
(2008)
Charge transport dynamics of polymer solar cells under operating conditions: Influence of trap filling
in Applied Physics Letters
Flesch H
(2009)
Charge transport properties and microstructure of polythiophene/polyfluorene blends
in Organic Electronics
Li Z
(2011)
Comparison of the Operation of Polymer/Fullerene, Polymer/Polymer, and Polymer/Nanocrystal Solar Cells: A Transient Photocurrent and Photovoltage Study
in Advanced Functional Materials
Vaynzof Y
(2012)
Compositional and Morphological Studies of Polythiophene/Polyflorene Blends in Inverted Architecture Hybrid Solar Cells
in Advanced Functional Materials
McNeill C
(2009)
Conjugated-Polymer Blends for Optoelectronics
in Advanced Materials
Zhang F
(2013)
Critical role of alkyl chain branching of organic semiconductors in enabling solution-processed N-channel organic thin-film transistors with mobility of up to 3.50 cm² V(-1) s(-1).
in Journal of the American Chemical Society
Brenner T
(2010)
Device physics of inverted all-polymer solar cells
in Journal of Applied Physics
Hwang I
(2009)
Drift-diffusion modeling of photocurrent transients in bulk heterojunction solar cells
in Journal of Applied Physics
Friedel B
(2009)
Effects of Layer Thickness and Annealing of PEDOT:PSS Layers in Organic Photodetectors
in Macromolecules
McNeill C
(2008)
Efficient Polythiophene/Polyfluorene Copolymer Bulk Heterojunction Photovoltaic Devices: Device Physics and Annealing Effects
in Advanced Functional Materials
McNeill C
(2009)
Evolution of Laterally Phase-Separated Polyfluorene Blend Morphology Studied by X-ray Spectromicroscopy
in Macromolecules
Hwang I
(2014)
Evolution of phase separation upon annealing and the influence on photocurrent generation in ternary blend organic solar cells
in Synthetic Metals
McNeill CR
(2008)
Evolution of the nanomorphology of photovoltaic polyfluorene blends: sub-100 nm resolution with x-ray spectromicroscopy.
in Nanotechnology
Friend RH
(2012)
Excitons and charges at organic semiconductor heterojunctions.
in Faraday discussions
Collins B
(2011)
Fullerene-Dependent Miscibility in the Silole-Containing Copolymer PSBTBT-08
in Macromolecules
Gwinner MC
(2012)
Highly efficient single-layer polymer ambipolar light-emitting field-effect transistors.
in Advanced materials (Deerfield Beach, Fla.)
Dalgleish S
(2011)
Indole-substituted nickel dithiolene complexes in electronic and optoelectronic devices
in Journal of Materials Chemistry
Friedel B
(2010)
Influence of Alkyl Side-Chain Length on the Performance of Poly(3-alkylthiophene)/Polyfluorene All-Polymer Solar Cells
in Chemistry of Materials
Yan H
(2010)
Influence of Annealing and Interfacial Roughness on the Performance of Bilayer Donor/Acceptor Polymer Photovoltaic Devices
in Advanced Functional Materials
Yan H
(2012)
Influence of dielectric-dependent interfacial widths on device performance in top-gate P(NDI2OD-T2) field-effect transistors
in Applied Physics Letters
He X
(2014)
Influence of Fluorination and Molecular Weight on the Morphology and Performance of PTB7:PC 71 BM Solar Cells
in The Journal of Physical Chemistry C
Friedel B
(2011)
Influence of solution heating on the properties of PEDOT:PSS colloidal solutions and impact on the device performance of polymer solar cells
in Organic Electronics
Yan H
(2011)
Interfaces in organic devices studied with resonant soft x-ray reflectivity
in Journal of Applied Physics
Campbell AR
(2008)
Low-temperature control of nanoscale morphology for high performance polymer photovoltaics.
in Nano letters
Watts B
(2011)
Mapping of Domain Orientation and Molecular Order in Polycrystalline Semiconducting Polymer Films with Soft X-Ray Microscopy
in Advanced Functional Materials
Schuettfort T
(2012)
Microstructure of polycrystalline PBTTT films: domain mapping and structure formation.
in ACS nano
Collins B
(2010)
Molecular Miscibility of Polymer-Fullerene Blends
in The Journal of Physical Chemistry Letters
Swaraj S
(2010)
Nanomorphology of bulk heterojunction photovoltaic thin films probed with resonant soft X-ray scattering.
in Nano letters
Gann E
(2014)
Near-edge X-ray absorption fine-structure spectroscopy of naphthalene diimide-thiophene co-polymers.
in The Journal of chemical physics
Schuettfort T
(2013)
Observation of a distinct surface molecular orientation in films of a high mobility conjugated polymer.
in Journal of the American Chemical Society
Oosterbaan W
(2013)
On the Relation between Morphology and FET Mobility of Poly(3-alkylthiophene)s at the Polymer/SiO 2 and Polymer/Air Interface
in Advanced Functional Materials
Gwinner M
(2012)
Organic field-effect transistors and solar cells using novel high electron-affinity conjugated copolymers based on alkylbenzotriazole and benzothiadiazole
in Journal of Materials Chemistry
Brenner T
(2011)
Phase-Dependent Photocurrent Generation in Polymer/Fullerene Bulk Heterojunction Solar Cells
in The Journal of Physical Chemistry C
McNeill C
(2009)
Photocurrent transients in all-polymer solar cells: Trapping and detrapping effects
in Journal of Applied Physics
McNeill C
(2009)
Photophysics and Photocurrent Generation in Polythiophene/Polyfluorene Copolymer Blends
in Advanced Functional Materials
Collins BA
(2012)
Polarized X-ray scattering reveals non-crystalline orientational ordering in organic films.
in Nature materials
Moore J
(2011)
Polymer Blend Solar Cells Based on a High-Mobility Naphthalenediimide-Based Polymer Acceptor: Device Physics, Photophysics and Morphology
in Advanced Energy Materials
Zaumseil J
(2008)
Quantum efficiency of ambipolar light-emitting polymer field-effect transistors
in Journal of Applied Physics
Burke K
(2009)
Role of Solvent Trapping Effects in Determining the Structure and Morphology of Ternary Blend Organic Devices
in Macromolecules
Watts B
(2010)
Simultaneous Surface and Bulk Imaging of Polymer Blends with X-ray Spectromicroscopy.
in Macromolecular rapid communications
Brenner T
(2011)
Spatially Resolved Spectroscopic Mapping of Photocurrent and Photoluminescence in Polymer Blend Photovoltaic Devices
in The Journal of Physical Chemistry C
Asadi K
(2011)
Spinodal Decomposition of Blends of Semiconducting and Ferroelectric Polymers
in Advanced Functional Materials
McNeill CR
(2010)
Structure of phase-separated ferroelectric/semiconducting polymer blends for organic non-volatile memories.
in Small (Weinheim an der Bergstrasse, Germany)
He X
(2012)
Studying polymer/fullerene intermixing and miscibility in laterally patterned films with X-ray spectromicroscopy.
in Small (Weinheim an der Bergstrasse, Germany)
Sciascia C
(2011)
Sub-micrometer charge modulation microscopy of a high mobility polymeric n-channel field-effect transistor.
in Advanced materials (Deerfield Beach, Fla.)
Schuettfort T
(2011)
Surface and Bulk Structural Characterization of a High-Mobility Electron-Transporting Polymer
in Macromolecules
Description | This EPSRC Advanced Fellowship for Dr Chris McNeill allowed him to develop a series of advanced structural probes, including synchrotron-based techniques, for characterisation of the microstructure of polymer electronics devices, particularly transistors and solar cells. Combined with device physics studies, this work has furthered our understanding of charge transport and photophysics relevant to improving device performance. |
Exploitation Route | The work will inform the optimisation of practical organic electronic devices, and provides structural probes that are of interest to researchers in other fields. |
Sectors | Electronics,Energy |
Description | The findings have assisted in the optimisation of polymer solar cells and transistors, accelerating their commercial application. |
First Year Of Impact | 2010 |
Sector | Electronics,Energy |
Impact Types | Economic |