CH3NH3PbBr3 Perovskite Nanocrystals Encapsulated in Lanthanide Metal-Organic Frameworks as a Photoluminescence Converter for Anti-Counterfeiting.

The increasing demands for optical anti-counterfeiting technology require the development of versatile luminescent materials with multiple models and tunable photoluminescence. Herein, the combination of luminescent perovskite nanocrystals and lanthanide-based metal-organic frameworks (Ln-MOFs) has been developed to offer such a high-tech anti-counterfeiting solution. The hybrid materials have been fabricated via the encapsulation of perovskite CH3NH3PbBr3 nanocrystals in europium-based metal-organic frameworks (Eu-MOFs) and they display multistage anti-counterfeiting behavior. CH3NH3PbBr3@Eu-MOF hybrids were developed in a two-step process, where the PbBr2@Eu-MOF precursor was formed first and, then, the composites can be formed quickly by the addition of CH3NH3Br into the precursors. Accordingly, the hybrid composites exhibited both excitation wavelength and temperature-dependent luminescence properties in the form of powders or films. Furthermore, the photoluminescence of the CH3NH3PbBr3@Eu-MOF composites can be quenched and recovered through water immersion and CH3NH3Br conversion, and the anti-counterfeiting applications have also been discussed. Therefore, this finding will open the opportunity to fabricate the hybrid materials with controlled photoluminescence properties, and it also acts as the emerging anti-counterfeiting materials in versatile fields.