Ultralong Organic Phosphorescence of Triazatruxene Derivatives for Dynamic Data Encryption and Anti-counterfeiting

Organic luminogens with persistent room temperature phosphorescence (RTP) have drawn tremendous attentions due to their promising potentials in optoelectronic devices, information storage, biological imaging, and anti-counterfeiting. In this work, six triazatruxene-based lumiogens with different peripheral substituents and configurations are synthesized and systematically studied. The results show that their fluorescence quantum yields in solid states range from 15.73% to 37.58%. Dispersing the luminogens as guest into the host (PPh3) could turn on the persistent RTP, where PPh3 acts as not only a rigid matrix to suppress the non-radiative transitions of the guest, but also provides energy transfer channels to the guest. The maximum phosphorescence efficiency and the longest lifetime could reach 29.35% and 0.99 s in co-crystal films of 6-TAT-CN/PPh3 and 5-TAT-H/PPh3, respectively. Moreover, these host-guest co-crystalline films exhibit great potentials in advanced dynamic data encryption and anti-counterfeiting. This work deepens the insight for low cost, halogen-free, and facile fabrication of all-organic persistent RTP materials.