Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 1, 2014
Previous Article Next Article

High work-function hole transport layers by self-assembly using a fluorinated additive

Author affiliations

Abstract

The hole transport polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) derives many of its favorable properties from a PSS-rich interfacial layer that forms spontaneously during coating. Since PEDOT:PSS is only usable as a blend it is not possible to study PEDOT:PSS without this interfacial layer. Through the use of the self-doped polymer sulfonated poly(thiophene-3-[2-(2-methoxyethoxy) ethoxy]-2,5-diyl) (S-P3MEET) and a polyfluorinated ionomer (PFI) it is possible to compare transparent conducting organic films with and without interfacial layers and to understand their function. Using neutron reflectometry, we show that PFI preferentially segregates at the top surface of the film during coating and forms a thermally-stable surface layer. Because of this distribution we find that even small amounts of PFI increase the electron work function of the hole transport layer. We also find that annealing at 150 °C and above reduces the work function compared to samples heated at lower temperatures. Using near edge X-ray absorption fine structure spectroscopy and gas chromatography we show that this reduction in work function is due to S-P3MEET being doped by PFI. Organic photovoltaic devices with S-P3MEET/PFI hole transport layers yield higher power conversion efficiency than devices with pure S-P3MEET or PEDOT:PSS hole transport layers. Additionally, devices with a doped interface layer of S-P3MEET/PFI show superior performance to those with un-doped S-P3MEET.

Graphical abstract: High work-function hole transport layers by self-assembly using a fluorinated additive

Back to tab navigation

Supplementary files

Article information


Submitted
24 May 2013
Accepted
26 Oct 2013
First published
30 Oct 2013

J. Mater. Chem. C, 2014,2, 115-123
Article type
Paper

High work-function hole transport layers by self-assembly using a fluorinated additive

S. A. Mauger, J. Li, Ö. T. Özmen, A. Y. Yang, S. Friedrich, M. D. Rail, L. A. Berben and A. J. Moulé, J. Mater. Chem. C, 2014, 2, 115
DOI: 10.1039/C3TC30973H

Social activity

Search articles by author

Spotlight

Advertisements