United we stand: Perovskite quantum dot/AIEgen hybrids with high optical stability and efficiency

Perovskite quantum dots and aggregation-induced-emission luminogens (AIEgens) are both widely investigated luminescent materials, yet they generally suffer from poor photostability. In this study, we fabricated a nanocomposite exhibiting exceptional stability and luminescence efficiency. Specifically, we grafted an AIEgen (TBBA), which has low single-molecular photoluminescence efficiency and poor photostability, onto the surface of CsPbBr ₃ perovskite quantum dots (QDs) that also have limited photostability. The intense absorption of CsPbBr ₃ QDs enabled them to function as optical antennas, efficiently transferring their excitons to the AIEgens in 43.1 ps with near-unity yield. This rapid extraction of the excitation energy from CsPbBr ₃ QDs and avoidance of ultraviolet photon absorption in AIEgens effectively solved the photostability issues for these two individuals, resulting in remarkable photostability with an effective half-life of 1800 days under simulated outdoor solar illumination. Additionally, strong restriction of intramolecular motions for AIEgens grafted onto the QD-surface led to near unity photoluminescence efficiency, with minimized reabsorption loss, which was leveraged to demonstrate high-efficiency, large-area luminescent solar concentrator devices. This study exemplifies how the principle of philosophical holism can guide the development of stable and bright optical composite materials from constituents with inherent poor stability and low emissivity.