The key role of nanoparticle seeds during site-selective growth of silver to fabricate core–shell or asymmetric dumbbell heterostructures

Abstract

Herein, a novel method to induce site-specific deposition of plasmonic silver domain on controlled sites of seeded AgBr nanoparticles is designed. Novel core-shell heterostructures and dumbbell heterostructures are fabricated by heterogeneous silver growth. A curved silver shell with thickness up to 5 nm is generated covering the AgBr core in the core-shell metal-semiconductor hybrids. However, in the dumbbell hybrids, a large silver domain is exclusively grown on a single side of the AgBr seed with a solid contact like relationship between the head and the tail. Photogenerated electrons are facilitated to transfer from the semiconductor head to the metal tail enhancing charge separations. The significant role of seed size during seeded silver growth has been demonstrated.