Ultralong room temperature phosphorescence from amorphous organic materials toward confidential information encryption and decryption

• Main Authors: Phua, Fiona Soo Zeng, Su, Yan, Li, Youbing, Zhou, Xianju, Jana, Deblin, Liu, Guofeng, Lim, Wei Qi, Ong, Wee Kong, Yang, Chaolong, Zhao, Yanli
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2018
• Subjects: Ultralong Room Temperature Phosphorescence (URTP); Amorphous Organic Molecules
• Online Access: https://hdl.handle.net/10356/85457; http://hdl.handle.net/10220/45162

Ultralong room temperature phosphorescence (URTP) emitted from pure amorphous organic molecules is very rare. Although a few crystalline organic molecules could realize URTP with long lifetimes (>100 ms), practical applications of these crystalline organic phosphors are still challenging because the formation and maintenance of high-quality crystals are very difficult and complicated. Herein, we present a rational design for minimizing the vibrational dissipation of pure amorphous organic molecules to achieve URTP. By using this strategy, a series of URTP films with long lifetimes and high phosphorescent quantum yields (up to 0.75 s and 11.23%, respectively) were obtained from amorphous organic phosphors without visible fluorescence and phosphorescence under ambient conditions. On the basis of the unique features of URTP films, a new green screen printing technology without using any ink was developed toward confidential information encryption and decryption. This work presents a breakthrough strategy in applying amorphous organic materials for URTP.