Indium Tin Oxide-Free Small Molecule Organic Solar Cells Using Single-Walled Carbon Nanotube Electrodes

Clément Delacou,Seungju Seo,Takafumi Nakagawa,Il Jeon,Yutaka Matsuo,Shigeo Maruyama,Esko I Kauppinen

doi:10.1149/2.0311706jss

Abstract

We demonstrated single-walled carbon nanotubes (SWNTs) electrode-based small molecule organic solar cells (OSCs) using diketopyrrolopyrrole donor, DPP(TBFu)2 as an electron donor with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as an electron acceptor. SWNT films with 60% transmittance (at 550 nm) were dry-transferred onto glass substrates to replace conventional indium tin oxide (ITO) electrodes. In order to improve the conductivity of the SWNT electrodes, MoOx thermal doping was applied followed by spin coating of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) to enhance doping and electrode blocking function. The indium-free devices showed a power conversion efficiency (PCE) of 1.00% while ITO-based devices showed a PCE of 3.79%.

Highlights

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Single-walled carbon nanotubes (SWNTs) films were prepared by direct and dry deposition of SWNTs grown by the floating catalyst, i.e., aerosol chemical vapor deposition technique and deposited on a nitrocellulose membrane.[25]
We produced SWNT films of 60% transparency at 550 nm and transferred them onto bare glass substrates. 15-nm-thick MoO3 was thermally deposited on the SWNT films and they were annealed at 300◦C for 2 hours under N2

Summary

Introduction

This material is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. We have already reported SWNT-based OSCs using low band-gap polymers as the electron donor, and produced a high PCE similar to that of the ITO reference devices.[6] Active layers were deposited by spin-coating at a rate of 4500 rpm for 60 s (optimized spin-coating for devices using ITO anode).

Results

Conclusion