# Transferable Plasmonic Arrays Enabling Strong Coupling with Layered Perovskites in an Active Diode Architecture

## TL;DR

Researchers developed a plasmonic cavity that strongly couples with layered perovskites, enabling efficient light-matter interactions for on-chip photonics.

## Contribution

A transferable plasmonic cavity is demonstrated for ultrastrong coupling with 2D perovskites using hexagonal boron nitride.

## Key findings

- Strong and ultrastrong coupling between excitons and cavity modes was observed with coupling factors up to 10% of resonance energy.
- Polariton mode hybridization and waveguiding led to line width narrowing below both cavity and exciton widths.
- Electrical excitation of hybrid modes was achieved via electron tunneling and energy transfer.

## Abstract

Plasmonic cavities provide a powerful platform for nanoscale
light
confinement far beyond the diffraction limit, enabling exceptionally
strong light-matter interactions. Recent advances in plasmonic architectures
and active materials enable stable, scalable routes toward fully integrated
on-chip photonics. In this work, we demonstrate the strong coupling
of 2D layered perovskites with a transferable plasmonic cavity directly
fabricated on top of hexagonal boron nitride (hBN). Under optical
excitation, we observe clear interaction between the exciton and cavity
modes leading to strong and even ultrastrong coupling, with coupling
factors g up to 10% of the resonance energy. Combined
with the polariton mode hybridization and a waveguiding effect, this
results in pronounced line width narrowing of the polariton modes
well below both the bare cavity and exciton line widths. Electrical
excitation of the hybrid modes is achieved via electron tunneling
and simultaneous energy transfer, making this design an attractive
configuration for on-chip integration.