Metal-Enhanced Photoluminescence in Perovskite Quantum Dots-hBN-Gold Film Mixed-Dimensional van der Waals Heterostructure

All-inorganic cesium lead halide perovskite quantum dots (QDs) have emerged as promising materials for next-generation optoelectronic devices due to their exceptional photoluminescence (PL) properties, including high quantum yields and narrow emission line widths. However, unlocking their full potential requires innovative strategies to further enhance and precisely tune their fluorescence efficiency. In this work, we present a novel 0D-2D-3D mixed-dimensional van der Waals (vdW) heterostructure comprising CsPbBr₃ QDs, multilayer hexagonal boron nitride (hBN), and a gold (Au) nanoparticle film, achieving a remarkable 7-fold PL enhancement. We attribute this enhancement to the synergy of plasmon-induced enhancement of the incident electromagnetic field and an increased spontaneous emission rate via the Purcell effect, optimized by tuning the hBN spacer thickness to 26 nm. This heterostructure design provides new insights into metal-enhanced photoluminescence for perovskite quantum dots, and it offers a scalable platform to enhance efficiency in future optoelectronic applications.