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

Artikel i vetenskaplig tidskrift, 2019

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.