Epitaxial growth of AuCN nanowires on graphene for hybrid phototransistors

Abstract

We present a facile method to fabricate epitaxially-grown semiconducting AuCN nanowires on graphene and investigate the evolution of nanowire morphology depending on growth conditions. The nanowire morphology and its directional alignment relative to graphene substrate are studied in detail with transmission electron microscopy, which clearly reveals the effect of diffusion kinetics during the nanowire formation process. We also investigate the electrical properties of AuCN/graphene heterostructures and their phototransistor behaviors. We find that the AuCN-sensitized hybrid device strongly responses to photons with energy above 2.6 eV, which is consistent with the bandgap of semiconducting AuCN. The device show a large UV response with responsivity ~ 104 A/W under the illumination of 3.1 eV (400 nm) photon.