Water dispersion of reduced graphene oxide stabilized via fullerenol semiconductor for organic solar cells

• Published in: Optical materials express 2017-07, Vol.7 (7), p.2487
• Main Authors: Lee, Sehyun, Yeo, Jun-Suk, Yun, Jin-Mun, Kim, Dong-Yu
• Format: Article
• Language: English
• Subjects: Graphene; Organic chemistry; Photovoltaic cells; Properties (attributes); Reduction; Solar cells; Surfactants
• ISSN: 2159-3930; 2159-3930
• DOI: 10.1364/OME.7.002487

To obtain solution-processable graphene in bulk-quantities, the chemical route was widely used to prepare graphene oxide (GO); however, the reduction process was inevitably needed to transform insulating GO into semi-metallic reduced graphene oxide (rGO). Therefore, to obtain stable rGO dispersions, many researchers introduced insulating surfactants that prevent irreversible aggregation. Although insulating surfactants were introduced to produce the stable dispersion of rGO, some properties of rGO, such as its dispersibility, processability, and electricity, are still problematic. In order to solve these problems, we synthesized novel rGO (F-OH-rGO) using the reduction process after blending GO and fullerenol (F-OH). By replacing insulating polymers with semiconducting and highly water-soluble F-OH, F-OH-rGO with not only higher conductivity but also a high dispersion concentration as well as film-forming properties could be achieved. We introduced various GO derivatives as hole-transporting layers (HTLs) to organic solar cells (OSCs) with discrepancies in important properties, so the fabricated solar cells manifested significant differences in their performances as we expected.