Purcell-Enhanced Spontaneous Emission from Perovskite Quantum Dots Coupled to Plasmonic Crystal

Lead halide perovskite quantum dots (PQDs) have recently been proposed as scalable and color-tunable single emitters, but their slow spontaneous emission (1–10 ns) creates a mismatch with high-speed nanophotonic devices. Here, we demonstrate Purcell enhanced emission rate in hybrid structure of PQDs coupled to plasmonic crystal at room temperature. A series of planar devices are produced in large scale via chemistry assembly using colloidal PQDs, Ag nanocubes, and polyvinylpyrrolidone (PVP) as building blocks. By varying the PVP spacer thickness as well as Ag nanocube surface density, a tunable photoluminescence enhancement is realized in both steady and time-resolved measurements. We show a 3.5-fold enhancement in the total fluorescence intensity and simultaneously an increase in the emission rate of a factor of 4.5. Finally, a proof-of-concept tag using PVP spacer encoded inks is demonstrated, providing a promising approach for information security based on Purcell-enhanced emission.