Quantifying the extent of contact doping at the interface between high work function electrical contacts and poly(3-hexylthiophene) (P3HT)

Shallcross RC, Stubhan T, Ratcliff EL, Kahn A, Brabec C, Armstrong NR (2015)


Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2015

Journal

Publisher: American Chemical Society

Book Volume: 6

Pages Range: 1303-1309

Journal Issue: 8

DOI: 10.1021/acs.jpclett.5b00444

Abstract

We demonstrate new approaches to the characterization of oxidized regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) that results from electronic equilibration with device-relevant high work function electrical contacts using high-resolution X-ray (XPS) and ultraviolet (UPS) photoelectron spectroscopy (PES). Careful interpretation of photoemission signals from thiophene sulfur atoms in thin (ca. 20 nm or less) P3HT films provides the ability to uniquely elucidate the products of charge transfer between the polymer and the electrical contact, which is a result of Fermi-level equilibration between the two materials. By comparing high-resolution S 2p core-level spectra to electrochemically oxidized P3HT standards, the extent of the contact doping reaction is quantified, where one in every six thiophene units (ca. 20%) in the first monolayer is oxidized. Finally, angle-resolved XPS of both pure P3HT and its blends with phenyl-C61-butyric acid methyl ester (PCBM) confirms that oxidized P3HT species exist near contacts with work functions greater than ca. 4 eV, providing a means to characterize the interface and "bulk" region of the organic semiconductor in a single film.

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How to cite

APA:

Shallcross, R.C., Stubhan, T., Ratcliff, E.L., Kahn, A., Brabec, C., & Armstrong, N.R. (2015). Quantifying the extent of contact doping at the interface between high work function electrical contacts and poly(3-hexylthiophene) (P3HT). Journal of Physical Chemistry Letters, 6(8), 1303-1309. https://dx.doi.org/10.1021/acs.jpclett.5b00444

MLA:

Shallcross, R. Clayton, et al. "Quantifying the extent of contact doping at the interface between high work function electrical contacts and poly(3-hexylthiophene) (P3HT)." Journal of Physical Chemistry Letters 6.8 (2015): 1303-1309.

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