Optically‐Controlled Quantum Size Effect in a Hybrid Nanocavity Composed of a Perovskite Nanoparticle and a Thin Gold Film

Abstract

Metal halide perovskites have attracted great interest in recent years and their emission wavelength can be adjusted either by doping impurities or by exploiting quantum size effect. Here, it is reported that the realization of optically‐controlled quantum size effect in a hybrid nanocavity composed of a perovskite (CsPbBr3) nanoparticle and a thin gold (Au) film. Such nanocavities are created by synthesizing polycrystalline CsPbBr3 nanoparticles composed of quantum dots on a thin Au film via chemical vapor deposition, which emit luminescence at ≈488 nm under the excitation of femtosecond laser pulses with a low repetition rate. The phase transition from polycrystalline to monocrystalline, which quenches the quantum size effect and shifts the emission wavelength to ≈515 nm, can be introduced in CsPbBr3 nanoparticles by simply increasing the laser power. Interestingly, such a phase transition is reversible provided that the laser power is lower than a threshold. Consequently, four optical states including dual‐wavelength emission, can be achieved by deliberately setting the laser power. The underlying physical mechanism is unveiled by the static and transient temperature distributions simulated for the hybrid nanocavity. The findings open a new avenue for designing novel photonic devices based on perovskite nanoparticles and plasmonic nanostructures.

Exciting Hybrid Optical Modes with Fano Lineshapes in Core–Shell CsPbBr3 Microspheres for Optical Sensing

“…The diameter of the microsphere is estimated to be ∼1.5 μm. Previously, CsPbBr 3 nanospheres with small diameters of ∼300–500 nm were synthesized using the same method . Such CsPbBr 3 nanospheres exhibited a core–shell structure based on the transmission electron microscopy (TEM) observations and X-ray photoelectron spectroscopy (XPS) measurements (see the Supporting Information, Note S4), which are different from the CsPbBr 3 nanospheres reported in previous studies. ,, In refs and , the substrate was placed about ∼8 cm downstream from the furnace center where the precursors (CsBr and PbBr 2 powders) were located.…”

“…As discussed above, it is suspected that the synthesized CsPbBr 3 microspheres generally exhibit a core–shell structure based on the previous studies on the synthesis of CsPbBr 3 microspheres, as schematically shown in Figure b. While the core is made of crystalline CsPbBr 3 , the shell is composed of CsBr and PbBr 2 nanocrystals.…”

Advances in metal halide perovskite lasers: synthetic strategies, morphology control, and lasing emission

“…14(c)]. Most recently, Li et al 166 proposed a hybrid nanocavity composed of CsPbBr 3 nanoparticles and a thin Au film, which could realize optically controlled quantum size effect by the reversible phase transition from polycrystalline to monocrystalline [Fig. 14(d)].…”

Development of Solution-Processed Perovskite Semiconductors Lasers

“…The device was deposited on a silicon-based substrate in which TiN served as a promising resonance-tunable plasmonic platform. In 2021, Lan's group reported polycrystalline CsPbBr 3 NPs composed of QDs on a thin Au film, exhibiting optically-controlled quantum size effect [89]. However, it is regrettable that their CsPbBr 3 NPs were synthesized by using chemical vapor deposition rather than the solution.…”