A Phase Diagram of the P3HT:PCBM Organic Photovoltaic System: Implications for Device Processing and Performance

DOI: 10.1021/ma102524a

Authors: Paul Hopkinson (University of Cambridge) , Paul Staniec (University of Sheffield) , Andrew Pearson (University of Sheffield) , Alan Dunbar (University of Sheffield) , Tao Wang (University of Sheffield) , Anthony J. Ryan (University of Sheffield) , Richard A. L. Jones (University of Sheffield) , David Lidzey (University of Sheffield) , Athene Donald (University of Cambridge)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Macromolecules , VOL 44 (8)

State: Published (Approved)
Published: March 2011
Diamond Proposal Number(s): 1203

Abstract: This paper describes the construction of a phase diagram for the as-cast state in the organic photovoltaic system P3HT:PCBM. Evidence for a transition to a phase-separated state at PCBM concentrations greater than 70 wt % is seen both by DMTA and GIWAXS, and the glass transition temperatures of blends in the single phase state below 70 wt % PCBM are observed to be raised compared to the pure polymer. Pure PCBM is observed to exhibit a thermal transition at 155 °C, an observation unreported to date-offering insight into crystallites commonly seen in device films. The liquid-crystal phase of P3HT is shown to persist in the presence of up to 41 wt % PCBM. In addition, pure PCBM is shown to be significantly hygroscopic, with important implications for the processing of high-performance devices.

Subject Areas: Energy


Instruments: I16-Materials and Magnetism

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