Perovskite Nanocrystals as Emerging Single-Photon Emitters: Progress, Challenges, and Opportunities

TL;DR

Perovskite nanocrystals are promising quantum emitters with high efficiency and tunability, but face stability challenges; recent advances aim to enhance their quantum light emission for practical applications.

Contribution

This review summarizes recent progress, compares PNCs with other emitters, and discusses strategies to improve their stability and quantum emission properties.

Findings

PNCs exhibit high photoluminescence quantum yield and single-photon purity.

Surface passivation and cavity coupling improve emission stability and indistinguishability.

Emerging strategies are reducing environmental stability issues.

Abstract

Metal-halide perovskite nanocrystals (PNCs) have emerged as leading candidates for next-generation quantum emitters, offering a unique combination of high photoluminescence quantum yield, tunable emission, short radiative lifetimes, and record-high single-photon purity under ambient conditions. These properties, together with low-cost and scalable solution-phase fabrication, position PNCs as attractive alternatives to traditional epitaxial and colloidal quantum dots. In this Review, we outline the physical parameters that define quantum emission in PNCs, compare their performance to other established and emerging quantum emitters, and assess the key figures of merit, including photostability, single-photon purity, and photon indistinguishability, required for practical quantum applications. We discuss underlying mechanisms affecting PNC emission behavior and highlight recent advances in improving their quantum emitting properties through synthetic and photonic engineering approaches. While challenges related to environmental stability and photon indistinguishability remain, emerging strategies, such as surface passivation, metal ion doping, and coupling with electromagnetic nano- and micro-cavities, are steadily closing the gap between PNCs and ideal quantum light sources.