Color-Tunable Mixed-Cation Perovskite Single Photon Emitters

TL;DR

This paper presents a chemical synthesis method for creating mixed-cation perovskite quantum dots that are highly stable and spectrally tunable at room temperature, suitable for quantum photonic applications.

Contribution

It introduces a new chemical approach to produce color-tunable, stable single photon emitters using mixed-cation perovskite quantum dots, expanding the spectral range for quantum photonics.

Findings

Achieved over 30 nm spectral tunability in visible range.

Maintained excellent single photon emission stability.

Demonstrated compositionally tunable electronic band structure.

Abstract

Quantum photonics technologies like wavelength division multiplexing (WDM) for high-rate quantum key distribution require narrowband, spectrally tunable single photon emitters. Physical methods that rely on the application of large mechanical strain to epitaxial quantum dots or electric and magnetic fields to color centers in 2D metal dichalcogenides provide limited spectral tunability. Here we adopt a chemical approach to synthesize a family of colloidal mixed-cation perovskite quantum dots ($\text{Cs}_{1-x}\text{FA}_{x}\text{PbBr}_3$) that show highly photo-stable, compositionally tunable single photon emission at room temperature - spanning more than 30 nm in the visible wavelength spectral range. We find that, tailoring the stoichiometry of the organic formamidinium (FA) cation in all-inorganic cesium lead bromide ($\text{CsPbBr}_3$) perovskite quantum dots detunes the electronic band structure while preserving their excellent single photon emission characteristics. We argue that the mixed-cation perovskite quantum dots studied in this work offer a new platform for the realization of color-tunable single photon emitters that could be readily integrated in a diversity of quantum photonic devices.