Graphene oxide as a multi-functional p-dopant of transparent single-walled carbon nanotube films for optoelectronic devicesElectronic supplementary information (ESI) available. See DOI: 10.1039/c2nr31923c

• Main Authors: Han, Joong Tark, Kim, Jun Suk, Jo, Sae Byeok, Kim, Sung Hun, Kim, Jong Soo, Kang, Boseok, Jeong, Hee Jin, Jeong, Seung Yol, Lee, Geon-Woong, Cho, Kilwon
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c2nr31923c

Modulation of electronic structures and surface properties of transparent carbon nanotube films is a challenging issue for their application in optoelectronic devices. Here, we report, for the first time, that graphene oxide (GO) nanosheets play the role of a p-doping agent and surface energy modifier of single-walled carbon nanotube (SWCNT)-based transparent conducting electrodes (TCEs). The deposition of highly oxidized, small-sized ( i.e. , diameter of less than 500 nm) GO nanosheets onto a SWCNT network film reduces the sheet resistance of the pristine film to 60% of its original value by p-doping. The modified TCEs exhibit an outstanding optoelectronic feature of high conductivity with high transparency. Moreover, the wettability of the electrode surface was also noticeably increased, which is advantageous for the solution-based processing of organic electronics. Furthermore, the organic photovoltaic (OPV) cells with the GO-doped SWCNT anodes on flexible substrates were successfully demonstrated. In stark contrast to a power conversion efficiency of 0.44% for pristine SWCNT anodes, GO-doped SWCNT anodes show a drastically enhanced power conversion efficiency of 2.7%. Size-sorted GO nanosheets were used as the multifunctional p-dopant for SWNT electrodes in flexible organic optoelectronic devices on a plastic substrate.