Ultrastrong coupling of CdZnS/ZnS quantum dots to bonding breathing plasmons of aluminum metal–insulator–metal nanocavities in near-ultraviolet spectrum

Abstract

Ultrastrong coupling in the near-UV range between aluminum metal–insulator–metal cavities and CdZnS/ZnS quantum dots is revealed by using cathodoluminescence; at the same time, the plexcitonic modes are spatially mapped at the deep-subwavelength scale.

Exciton–Photonics: From Fundamental Science to Applications

“…Likewise, QDs with random dipole moments that are deterministically placed in plasmonic nanocavities such as bowtie antennas have also shown evidence of strong coupling. (6,(68)(69)(70)(71)113) Single dye coated plasmonic particles, (120,(123)(124)(125)(126)(127)(128) and particle on the metallic substrate (75,129) as well as electrical injection in J-aggregate/GaN microcavity up to 200 K. (130) In these studies, the J-aggregates with excitonic absorption peak between 2.25 -2.48 eV form hybrid states with silver plasmonic particles. (120,(123)(124)(125)(126)(127)(128) Although silver supports visible plasmon, the narrow interband transition in aluminum (~1.5 eV) allows it to extend the surface plasmon response up to the ultraviolet range and also as a low-cost alternative to silver.…”

“…Likewise, QDs with random dipole moments that are deterministically placed in plasmonic nanocavities such as bowtie antennas have also shown evidence of strong coupling. 6,[71][72][73][74]148 Single-particle probe techniques such as cathodoluminescence were used to probe especially large Rabi splittings (∼1200 meV) from individual CdZnS/ CdS QDs placed in Al nanocavities. 74 For a detailed account on the strong light−matter coupling in inorganic QDs measured in the far-field, the readers are referred to previously published review articles.…”

“…6,[71][72][73][74]148 Single-particle probe techniques such as cathodoluminescence were used to probe especially large Rabi splittings (∼1200 meV) from individual CdZnS/ CdS QDs placed in Al nanocavities. 74 For a detailed account on the strong light−matter coupling in inorganic QDs measured in the far-field, the readers are referred to previously published review articles. 54,55 Akin to inorganic QDs, functionalized SWCNTs have also shown evidence of strong light−matter coupling from the reflectance spectroscopy studies.…”

“…(A) Comparison of different cavity mode (microcavity, resonator, photonic cavity, and micropillars) shows that the plasmonic cavity can achieve strong coupling at 300 K due to its ultrasmall mode volume despite a low Q factor. (B) Excitonic materials, namely, QDs, ,− organic molecules (0D), − SWCNTs, − perovskites (1D), − J-aggregates, − , 2D HOIP, − 2D TMDC monolayers, − and 3D TMDC multilayers ,,− studied in cavity mode. Rabi splitting (ℏΩ) to transition dipole moment (μ) as a figure of merit (ℏΩ/μ) is compared for these excitonic materials.…”

“…0D materials such as organic molecules and QDs support Frenkel excitons and Wannier–Mott excitons, respectively. − Evidence of strong light–matter coupling has been presented in organic molecules such as methylene blue positioned in plasmonic nanocavities with their dipole moment along the cavity electric field. Likewise, QDs with random dipole moments that are deterministically placed in plasmonic nanocavities such as bowtie antennas have also shown evidence of strong coupling. ,− , Single-particle probe techniques such as cathodoluminescence were used to probe especially large Rabi splittings (∼1200 meV) from individual CdZnS/CdS QDs placed in Al nanocavities . For a detailed account on the strong light–matter coupling in inorganic QDs measured in the far-field, the readers are referred to previously published review articles. , …”