Photoluminescence enhancement by exciton-plasmon coupling in MAPbI3 quantum dots on gold nanorods

Localized surface plasmon resonance (LSPR) is widely studied for its role in enhancing optical properties and facilitating charge or energy transfer through exciton-plasmon interactions in materials such as organic dyes, chalcogenide and halide perovskite quantum dots (PQDs), and transition-metal dichalcogenides (TMDCs). LSPR coupling with perovskite nanocrystals (PNCs) and quantum dots (QDs) has gained significant attention due to their outstanding electronic and optical properties. However, the precise effects of LSPR on the exciton dynamics of PQDs remain largely unexplored. This study focuses on exciton-plasmon coupling between gold nanorods (Au NRs) and individual methylammonium lead iodide (MAPbI₃) PQDs using single-particle blinking analysis. While PQDs without Au display a slow ON-OFF (long-lived ON and OFF states) blinking behavior, those on Au NRs exhibit short-lived, high-intensity ON states. This difference in blinking dynamics is attributed to energy transfer from Au NRs to PQDs through exciton-plasmon interactions and chemical interface damping. Further investigation through single-particle time-resolved photoluminescence measurements and ensemble-level transient absorption spectroscopy reveals that plasmon coupling enhances radiative recombination while expediting the ground-state bleach-recovery via energy transfer. Additionally, spatial variations in QD distributions on AU NRs are examined using transmission electron microscopy, high-resolution scanning transmission electron microscopy, and finite-difference time-domain simulations, providing deeper insight into the nature of exciton-plasmon interactions. This study explores how tiny particles called perovskite quantum dots (PQDs) interact with gold nanorods to enhance light emission. PQDs blink on and off when they emit ligh but when placed on gold nanorods, they emit brighter and more stable light. This is due to a phenomenon called exciton-plasmon coupling, where the PQDs and gold nanorods exchange energy. Researchers prepared PQDs without protective layers and observed their behavior on glass and gold nanorod surfaces. They used various techniques like single-particle imaging and time-resolved photoluminescence to study these interactions. The study found that PQDs on gold nanorods showed up to 13 times more intense light emission compared to those on glass. The findings suggest that this interaction can improve the performance of devices like solar cells and LEDs by making them more efficient in converting light into energy. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. In this article, we explore the coupling between the localized surface plasmon of gold nanorods and the excitonic states of methylammonium lead iodide (MAPbI3) perovskite quantum dots. Using single-molecule fluorescence microscopy, time-resolved fluorescence spectroscopy, transient absorption spectroscopy, and finite-difference time-domain simulations, we reveal the origin of exciton-plasmon-coupled blinking suppression and emission intensity enhancement in the gold nanorod-MAPbI3 quantum dot system.