Our research explores the potential of zero-dimensional perovskite nanocrystals (0D PNCs) embedded in a three-dimensional (3D) perovskite matrix as high-performance emitters for next-generation light-emitting diodes (LEDs). While conventional 3D perovskite LEDs (PeLEDs) exhibit promising electroluminescence (EL), their efficiency and stability are often limited by nonradiative recombination, ion migration, and spectral instability under operational conditions. In contrast, 0D PNCs, such as Cs₄PbBr₆ (green-emitting) and Cs₄PbI₆ (red-emitting), demonstrate near-unity photoluminescence quantum yields (PLQYs) and suppressed Auger recombination due to strong quantum confinement. However, their insulating nature hinders charge transport in optoelectronic devices.
(a) Illustration of the fabrication method for dispersing 0D perovskites in a 3D matrix (b) Ionic redistribution and charge dynamics in PeLECs.
By integrating highly emissive 0D PNCs into a conductive 3D perovskite (e.g., CsPbBr₃) matrix via solvent engineering, we achieve a synergistic composite that combines the high radiative efficiency of 0D PNCs with the excellent charge transport of 3D perovskites. This hybrid architecture enables enhanced electroluminescence, operational stability, and thermally activated delayed photoluminescence (TADP). This has advantages over conventional systems as the scalability avoids the complexity of epitaxial growth used in quantum dot LEDs (QLEDs), its spectral purity lets it exhibit narrow emission linewidths (<25 nm), ideal for color-pure displays, and it has better defect tolerance over bulk perovskites. (ACS Energy Lett. 2021, 6, 10, 3695–3708; Adv. Mater. 2022, 34, 2203226; J. Phys. Chem. Lett. 2023, 14, 12, 2933–2939)
(c) Luminance versus voltage for 3D and 3D-0D PeLECs. Inset: Operation of a 3D-0D (high PLQY) PeLEC at 4.5 V. (d) EQE vs.voltage for 3D and 3D-0D PeLECs. e) Power efficiency vs. voltage for 3D and 3D-0D PeLECs.
We aim to extend this approach to blue-emitting 0D PNCs (e.g., Cs₄PbCl₆) and explore their integration into electrically driven single-photon sources for quantum communication. By leveraging the TADP mechanism and further optimizing charge injection, we envision PeLEDs that meet the efficiency and stability benchmarks for industrial adoption in displays, lighting, and quantum photonics.