Deep information-hiding based on cascade thermoresponsive luminescence switching of A-π-D-π-A typed carbazole derivatives

Protecting the confidential information by hiding its existence exhibits great security. To achieve this, the materials showing several distinct luminescent states upon continuous external stimuli are eagerly anticipated because they can provide pseudo-information to avoid the true-information being discerned easily. Herein, aiming to realize the multi-responsive luminescent signals upon thermal stimulus, four A-pi-D-pi-A typed carbazole luminophores were elaborately developed with the molecular configuration varied from linear to Vshape via positional isomerism. It was demonstrated that the V-shaped 3,5-h-CPDI with the largest dipole moment exhibited heating-quenching-triggered cascade luminescence off-on-off-on-off switches in temperature cycles of 25-209-255-25-136 degrees C. The linear-shaped 2,7-h-CPDI with the smallest dipole moment only exhibited thermal induced emission quenching. Based on these, using the samples of 3,5-h-CPDI and 2,7-h-CPDI in different luminescent states as the codes, and heating as the tool for information writing and reading-out, deep information-hiding with true-information being hidden under a series of pseudo-information was realized. This work provides a promising way for deep information-hiding through advanced thermoresponsive luminescent materials.

Automated summary

By developing carbazole luminophores with different molecular configurations, the study demonstrated the potential of achieving multi-responsive luminescent signals under thermal stimulus, providing a promising way for deep information-hiding.