Organic Circularly Polarized Room-Temperature Phosphorescence Toolbox with Excellent Practicality and Functionality.

Abstract

Development of high-performance and practical circularly polarized room-temperature phosphorescent (CPRTP) materials continues to pose a significant challenge. Herein, we demonstrated a series of easy-to-scale organic RTP materials with circularly polarized luminescence, tunable responsiveness, high quantum yield, good flexibility, and excellent water resistance, achieved via a simple blending process with cyanoethyl cellulose (CEC) as the matrix. The cyano groups in CEC facilitated dipole-π interactions, while the hydroxyl groups provided hydrogen bonding interactions, collectively restricting the mobility of aromatic molecules and polymer chains to suppress the nonradiative transitions. By incorporation of different aromatic molecules, RTP materials with full-color emission were achieved from blue to cyan, yellow, orange, and red. These materials also exhibited irradiation-time dependence and visible-light excitation. Their phosphorescence performance was enhanced after acid treatment. The photoluminescence and phosphorescence quantum yields reached 40.0% and 13.3%, respectively. Using common polymer processing techniques, we fabricated large-area flexible RTP films and diverse phosphorescent 3D objects with good mechanical properties. More importantly, the materials had high stability, retaining phosphorescence performance even after immersion in water and salt solutions for 120 days. Such high-stable, flexible, easy-to-process, full-color, and high-performance CPRTP materials hold a huge potential in display, anticounterfeiting, and information encryption.