A multifunctional emitter with synergistical adjustment of rigidity and flexibility for high-performance data-recording and organic light-emitting devices with hot exciton channel

An intramolecular dual-locking design is proposed for organic luminescent materials, aiming at synergistically adjusting the molecular rigidity and flexibility for applications in data storage and light-emitting devices. According to this concept, a multifunctional donor-acceptor type emitter, LPCz-TRZ, is developed, featuring a soft diphenylmethane lock and a hard single-bond lock in its donor moiety. The highly locked structure results in appreciable rigidity that endows LPCz-TRZ with high luminescence efficiency, narrow emission, promoted charge conductivity and triplet harvesting hot exciton channels, allowing high-performance deep-blue organic light-emitting diodes (OLEDs) with an external quantum efficiency as high as 7.88%, which is among the best deep-blue hot exciton OLEDs. Notably, the structure of LPCz-TRZ is semi-flexible, leading to unique mechanochromic luminescence (MCL) behavior. Compared to the conventional MCL emitters, the orchestration of rigidity and flexibility in LPCz-TRZ affords high-contrast, fatigue-resistance MCL, as evidenced by a simple, rewritable data-recording demonstration with negligible fatigue after up to 15 wiring-erasing cycles.

Automated summary

This study proposes an intramolecular dual-locking design for organic luminescent materials, achieving high luminescence efficiency and performance for deep-blue organic light-emitting diodes. The material also exhibits unique mechanochromic luminescence behavior and strong fatigue resistance.