Two‐Photon Ionization Induced Stable White Organic Long Persistent Luminescence

• Published in: Angewandte Chemie International Edition Vol. 60; no. 31; pp. 16984 - 16988
• Main Authors: Liang, Xiao, Zheng, You‐Xuan, Zuo, Jing‐Lin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 26.07.2021
• Edition: International ed. in English
• Subjects: Color; Excitons; Ionization; Luminescence; Optimization; organic room temperature phosphorescence; persistent luminescence; Phosphine; Phosphine oxide; Photons; two-photon ionization; white afterglow
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202106472

Organic long persistent luminescence (OLPL) materials with afterglow duration in the scale of minutes or even hours are still rare. Most OLPL systems are based on exciplexes, which require complicated multi‐component system in order to realize white afterglow but with slightly compromised duration and color stability. In this work, OLPLs lasting from 20 to 40 minutes are realized in a simple binary system based on two‐photon ionization mechanism, which can simultaneously harvest excitons from both singlet and triplet excited states, making it potentially one of the most promising candidates to achieve stable white OLPL. Through modulation and optimization of dopant molecules in dibenzo[b,d]thiophen‐2‐yldiphenyl phosphine oxide host, the emission profiles of afterglow can be readily tuned from cyan (0.19, 0.22), cold white (0.31, 0.35), standard white (0.33, 0.33) to warm white (0.31, 0.46), with excellent color consistency. Organic long persistent luminescence with afterglow lasting up to 20–40 minutes was achieved based on two‐photon ionization mechanism at room temperature in a simple binary system. Through modulation of molecular structures and potential ISC channels between excited states, the afterglow profiles can be rationally tuned from cyan (0.19, 0.22), cold white (0.31, 0.35), standard white (0.33, 0.33) to warm white (0.31, 0.46).