Highly Efficient Organic-Graphene Hybrid Photodetectors via Molecular Peripheral Editing

Abstract

Hybrid systems based on graphene and organic molecules are highly appealing for “correcting” the limited optoelectronic properties of the 2D material. However, in-depth understanding of the correlation between the structure of the molecular sensitizer and the physical properties of the hybrid toward high-performance organic-graphene hybrid photodetectors remains elusive. Herein, ad-hoc molecular design via a peripheral editing approach on the organic molecules is employed to elucidate the structure-property relationship when interfaced to graphene forming hybrid systems. Efficient doping of graphene can be attained by physisorption of tetrathiafulvalene molecules exposing electron-donating peripheral groups, benefiting from a strong coupling yielding efficient charge transfer, ultimately leading to photodetectors with ultra-high responsivity of 1.1 × 107 A/W and specific detectivity of 6.5 × 1014 Jones, thereby outperforming state-of-the-art graphene-based photodetectors. These results offer valuable insights for future optimization of graphene-based photodetectors through molecular functionalization.