Functionalized reduced graphene oxide with tunable band gap and good solubility in organic solvents

• Published in: Carbon (New York) Vol. 146; pp. 491 - 502
• Main Authors: Méndez-Romero, Ulises A., Pérez-García, Sergio A., Xu, Xiaofeng, Wang, Ergang, Licea-Jiménez, Liliana
• Format: Journal Article
• Language: English
• Published: New York Elsevier Ltd 01.05.2019; Elsevier BV
• Subjects: Band gap; Chemical reduction; Conjugation; Electronics; Energy gap; Graphene; Nanoparticles; Organic chemistry; Photovoltaic cells; Semiconductor materials; Semiconductors; Silver; Solar cells; Solubility; Solvents
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2019.02.023

The materials intended for organic photovoltaics and organic electronics require specific properties, such as conjugation along backbones, good solubility in organic solvents and a suitable band gap. Graphene oxide holds a high indirect optical band gap of 3 eV and a hydrophilic behavior. However, based on the fact that the graphene oxide band gap is related to the C/O ratio, chemical reduction and functionalization must be performed to obtain the proper characteristics that are required for organic applications. Here an efficient approach for chemically modified graphene oxide as a low-cost alternative for organic semiconductor materials was developed. The two synthesized materials (functionalized reduced graphene oxide and functionalized reduced graphene oxide decorated with silver nanoparticles) exhibited a 65% and 52% band gap decrease respectively, compared to graphene oxide. Moreover, both materials were soluble in organic solvents at high concentrations [10 mg mL−1], turning them suitable for many applications, including organic electronics, with the additional advantage of being a solution process avoiding restacking of layers. [Display omitted]