Controlling Photoluminescence for Optoelectronic Applications via Precision Fabrication of Quantum Dot/Au Nanoparticle Hybrid Assemblies

Abstract

The distance-dependent interaction of an emitter with a plasmonic nanoparticle or surface forms the basis for the application of such systems within optoelectronics. Semiconductor quantum dots (QDs) are robust emitters due to their photostability. A key challenge is the formation of well-defined assemblies containing QDs and plasmonic nanoparticles in high purity. Here, we present the translation of DNA-based self-assembly to assemble metal and semiconductor nanocrystals into hybrid structures. The high purity of the assemblies, including dimers and higher-order core–satellite structures, allows fundamental investigation of the plasmon–exciton interaction. In contrast to the increase in the QD emission rate and enhancement in steady-state photoluminescence observed for overlap between the QD emission and localized surface plasmon resonance, significant detuning of these energies leads to lengthening of the QD emission lifetime (reduction of the emission rate) up to 1.7-fold and enhancement in steady-state photoluminescence of 15–75%. These results are understood in terms of the Purcell effect, where the gold nanoparticle acts as a damped, nanoscale cavity. We show that the response is driven by the interference experienced by the emitter for parallel and perpendicular field orientations. This provides a mechanism for control of the emission rate of a QD by a metal nanoparticle and a much wider range of lifetimes than previously understood.

Rich Landscape of Colloidal Semiconductor–Metal Hybrid Nanostructures: Synthesis, Synergetic Characteristics, and Emerging Applications

“…One of the most prominent factors to control the fluorescence enhancement is the distance between the plasmonic metal and the emitting semiconductor components. − Demonstration of the distance effect on emission enhancement in semiconductor–metal nanoparticles was reported for CdSe/ZnS core/shell nanoparticles deposited on Au colloids with a defined polyelectrolyte spacer allowing controlled distance between the semiconductor nanoparticles and the gold films . Maximum enhancement by a factor of 5 was achieved for a 9-layer spacer (∼11 nm) due to a local enhanced electromagnetic field around the metal nanostructures (Figure A).…”

“…Hybrid DNA-based assembly of CdSe/CdS with Au NPs and Au NRs showed a significant fluorescence enhancement of 15−75% depending on the different HNPS architectures in comparison to nonconjugated semiconductor NPs. 167 However, Au rod structures exhibit a greater magnitude of fluorescence enhancement (75% vs 48% for rods and spheres, respectively) due to the strong localization of the near field at the nanorod tips (Figure 19D).…”

“…Copyright 2010 American Chemical Society. (D) Adapted with permission from ref . Copyright 2022 American Chemical Society.…”

Nanoparticle Assembly: From Self‐Organization to Controlled Micropatterning for Enhanced Functionalities

“…Nanoparticle assembly is crucial in various application areas, including polymer composites, [ 444 ] thermal management, [ 462 ] microelectronics, [ 102 ] optical devices, [ 463 ] biomedical devices, [ 464 ] magnetic systems, [ 465 ] and biological sensing/detection. [ 466 ] Take the block copolymer‐nanoparticle composite as an example; the distinct morphologies exhibited by block copolymers, such as layered structures, gyroid structures, or hexagonally packed cylinders, offer confinement and organization sites for nanoparticles.…”

Prospects of Utilizing Quantum Emitters to Control the Absorption of Non‐Noble Plasmonic Metal Nanoparticles

“…[31][32][33] Hybrid nanostructures formed by combining plasmonic nanoparticles with excitonic emitters such as semiconductor nanocrystal quantum dots (SQDs) are gaining increasing research attention due to their unprecedented capabilities to manipulate light at the nanoscale. [34][35][36][37][38][39][40][41][42] In 2015, Hartsfield et al experimentally demonstrated the ability of a single SQD with a small scattering cross section to dramatically modify the scattering spectrum of a gold nanosphere kept at nanoscale proximity. [43] The result was stated as highly counter-intuitive as scattering cross sections of the two nanoparticles differed by several orders of magnitude.…”