Multicolor and multimodal luminescence in an Er3+ single-doped double perovskite for advanced anti-counterfeiting and encryption

Multicolor and multimodal luminescence materials play crucial roles in anti-counterfeiting and encryption technologies due to their attractive properties of colorful, visually identifiable emissions and distinct emission modes in various excitation or stimulus channels. Nevertheless, integrating multicolor and multimodal luminescence via single rare-earth doping based on a single matrix remains a significant challenge. Herein, the Er3+ single-doped NaGdTi1.8Al0.2O6 double perovskite material achieves multicolor luminescence, afterglow, and upconversion emission by responding to several types of excitation ranging from UV to NIR and thermal disturbance. Spectral analysis has revealed that the varying excitation efficiency of the two luminescence centers at various excitation wavelengths leads to a shift in the overall emission color from red to green as the excitation wavelength transitions from 250 nm to 390 nm. Additionally, the energy transfer process between defect levels and Er3+ leads to multicolor luminescence from green to orange within a temperature range of 217 K to 417 K. These findings offer a facile and unique strategy for designing highly integrated multicolor and multimodal luminescence in a single matrix and promise applications in advanced anti-counterfeiting and information encryption technology.