Multi-color UCNPs/CsPb(Br1-xIx) 3 for upconversion luminescence and dual-modal anticounterfeiting

Advanced hybrid materials have attracted extensive attention in optoelectronics and photonics application due to their unique and excellent properties. Here, the multicolor upconversion luminescence properties of the hybrid materials composed of CsPbX3(X = Br/I) perovskite quantum dots and upconversion nanoparticles (UCNPs, core-shell NaYF4(:)25%Yb3+,0.5%Tm3+@ NaYF4) is reported, achieving the upconversion luminescence with stable and bright of CsPbX3 perovskite quantum dots under 980 nm excitation. Compared with the nonlinear upconversion of multi-photon absorption in perovskite, UCNPs/CsPbX3 achieves lower power density excitation by using the UCNPs as the physical energy transfer level, meeting the demand for multi-color upconversion luminescence in optical applications. Also, the UCNPs/CsPbX3 combined with ultraviolet curable resin (UVCR) shows excellent water and air stability, which can be employed as multicolor fluorescent ink for screen printing security labels. Through the conversion strategy, the message of the security labels can be encrypted and decrypted by using UV light and a 980 nm continuous wave excitation laser as a switch, which greatly improves the difficulty of forgery. These findings provide a general method to stimulate photon upconversion and improve the stability of perovskite nanocrystals, which will be better applied in the field of anti-counterfeiting.

Automated summary

The multicolor upconversion luminescence properties of hybrid materials composed of CsPbX3 (X = Br/I) perovskite quantum dots and upconversion nanoparticles (UCNPs) are reported. This achieves stable and bright upconversion luminescence of CsPbX3 perovskite quantum dots under 980 nm excitation. By utilizing UCNPs as a physical energy transfer level, UCNPs/CsPbX3 achieves lower power density excitation compared to the nonlinear upconversion of multi-photon absorption in perovskite, meeting the demand for multi-color upconversion luminescence in optical applications. Combining UCNPs/CsPbX3 with ultraviolet curable resin (UVCR) results in excellent water and air stability, making it suitable for multicolor fluorescent ink in screen printing security labels. The conversion strategy allows the encryption and decryption of messages on the labels using UV light and a 980 nm continuous wave excitation laser as a switch, greatly enhancing forgery difficulty. These findings provide a general method to stimulate photon upconversion and improve the stability of perovskite nanocrystals, with potential applications in anti-counterfeiting.