Polarized Superradiance from CsPbBr₃ Quantum Dot Superlattice with Controlled Interdot Electronic Coupling.

Area of Science:

• Quantum Optics
• Materials Science
• Solid-State Physics

Background:

• Superradiance involves cooperative photon emission from electronically coupled quantum emitters.
• Perovskite quantum dots (QDs) rarely exhibit superradiance due to challenges in achieving electronic coupling.
• Superfluorescence, distinct from superradiance, occurs in incoherently excited QDs coupled to a common radiation mode.

Purpose of the Study:

• To investigate and achieve superradiance in perovskite quantum dots.
• To explore the potential of engineered perovskite QD superlattices for cooperative photon emission.
• To understand the role of electronic coupling in perovskite QD superradiance.

Main Methods:

• Fabrication of strongly coupled CsPbBr3 QD superlattices.
• Utilizing quantum confinement and ligand engineering to control interdot electronic coupling.
• Characterization of optical properties, including emission linewidth and polarization.

Main Results:

• Observation of superradiance with a narrow linewidth (<5 meV) and significant redshift (∼200 meV).
• Demonstration of polarized superradiance, contrasting with uncoupled exciton emission.
• Evidence of anisotropic electronic coupling within the QD superlattice.

Conclusions:

• Strongly coupled perovskite QD superlattices can exhibit superradiance.
• Ligand engineering and quantum confinement are effective strategies for achieving interdot coupling in perovskite QDs.
• Perovskite QD superlattices show promise as tunable, polarized cooperative photon emitters.