Semiconductor Bow?Tie Nanoantenna from Coupled Colloidal Quantum Dot Molecules

Top-down fabricated nanoantenna architectures of both metallic and dielectric materials demonstrated powerful functionalities for Raman fluorescence enhancement with relevance to single molecule sensing, while inducing directionality chromophore emission implications photon sources. Herein, we synthesize the smallest bowtie by selective tip-to-tip fusion two tetrahedral colloidal quantum dots (CQDs) forming a dimer. While monomers emit non-polarized light, architecture manifests functionality enhanced polarization along axis as predicted theoretically revealed particle spectroscopy. Theory also predicts formation an electric-field hotspot at epicenter. This is utilized light induced photocatalytic metal growth that location, unlike on free tips in dark conditions thus demonstrating dimer photochemical reaction center. Our findings pave path additional bottom-up applicable optics, sensing photocatalysis.