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 CH 3 NH 3 PbBr 3 nanocrystals in europium-based metal–organic frameworks (Eu-MOFs) and they display multistage anti-counterfeiting behavior. CH 3 NH 3 PbBr 3 @Eu-MOF hybrids were developed in a two-step process, where the PbBr 2 @Eu-MOF precursor was formed first and, then, the composites can be formed quickly by the addition of CH 3 NH 3 Br 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 CH 3 NH 3 PbBr 3 @Eu-MOF composites can be quenched and recovered through water immersion and CH 3 NH 3 Br 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.