Core-Shell Halide Perovskite Nanocubes for Low-Threshold Lasing Applications

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), vol. 10, pp. 1

Abstract

Metal halide perovskite nanostructures have attracted considerable attention in both fundamental and applied research, owing to their extraordinary optoelectronic properties such as emission tunability across the visible range, high photoluminescence quantum yield with narrow full-width at half-maximum (FWHM$\sim 20\ \text{nm}$) and high defect tolerance [1]–[3]. Recently, new perovskite structures such as nanocubes and superlattices have shown a novel type of emission called superfluorescence, which is not present in other low-dimensional perovskites like nanowires [4]–[6]. Superfluorescence can be promising to achieve low-threshold lasing, however, the Auger recombination in such systems has not been investigated. Here, we show a new route for the in-situ formation of perovskite nanocubes with edge lengths below 100 nm during spin coating from different halide compositions. Further, a solid-gas route to achieve core-shell perovskite nanocubes through a gas-solid halide exchange route will be presented. In particular, the core CsPbBr3 nanocubes were synthesized with a facile solution-based technique, where a perovskite solution containing cesium and lead bromide precursors was spin coated on selected substrate. The absence of luminescence in the precursor solution under UV exposure, but a later strong PL signal from the spin-coated film confirms the formation of nanocubes during the spin coating process. The growth and properties of nanocubes appear to be independent of the substrate. For instance, perovskite solution spin-coated on nickel oxide (NiOx), silicon (Si) / silicon oxide (SiO2) and glass, as well as two-dimensional layered molybdenum disulfide (MoS2) and hexagonal boron nitride (hBN) substrates leads to nanocube formation. The edge length of the spin coated CsPbBr3nanocubes was about 120 nm on a Si/SiO2substrate (Figure1a). CsPbBr3 nanocubes on large bandgap semiconductors (SiO2/Si or hBN) showed high photoluminescence intensity with an emission peak at 524 nm and FWHM of 20 nm (Figure 1b). However, we also observed a decrease in photoluminescence intensity at perovskite-3D (or 2D) interfaces promoting charge or energy transfer mechanisms. The core-shell heterojunctions were achieved by placing CsPbBr3nanocubes in Cl−ionic environment. The ion exchange reaction lead to the formation of CsPbBr3/CsPbBr3-xClxcore-shell nanocubes, which will be presented alongside their optical properties. Our study provides a route towards tuning the optical properties of CsPbBr3 nanocrystals by core shell configurations for low threshold lasing applications.

Authors 4

1. Sana Khan Aachen AMO GmbH

   AMO (Germany) · RWTH Aachen University

   Affiliation as printed

   AMO GmbH,Aachen,Germany,52074

   RWTH Aachen University, Aachen, Germany

2. Maryam Mohammadi Aachen AMO GmbH

   AMO (Germany)

   Affiliation as printed

   AMO GmbH,Aachen,Germany,52074

3. Surendra B. Anantharaman Aachen AMO GmbH

   AMO (Germany)

   Affiliation as printed

   AMO GmbH,Aachen,Germany,52074

4. Max C. Lemme Aachen AMO GmbH

   AMO (Germany) · RWTH Aachen University

   Affiliation as printed

   AMO GmbH,Aachen,Germany,52074

   RWTH Aachen University, Aachen, Germany