A highly luminescent porous metamaterial based on a mixture of gold and alloyed semiconductor nanoparticles

Abstract

Understanding the different processes in modern multicomponent metamaterials is a crucial task for their development. This includes the investigation of superstructures that can be formed by nanoparticle self-assembly. Here we present a destabilization-based synthetic protocol for the preparation of porous superstructures with flower, sphere, and spike-like shapes. This approach is universal for nanoparticles of various natures and compositions. We have prepared superstructures of the same architecture from alloyed quantum dots and their mixtures with gold nanoparticles. It was found that the concentration of gold nanoparticles strongly affects the QD optical properties in the superstructure: a 2.5-times PL enhancement for a 2% Au nanoparticle content is reported. We offer a detailed model describing the stages of superstructure formation and reveal the mechanisms behind this. Material-indifferent means of control over the shape and properties of self-assembled superstructures give us a new functional tool for developing metamaterials with potential applications in sensorics.