Abstract
Stimuli responsive luminescent materials, especially those exhibiting multicolor emission switching, have potential application in sensor, optical recording, security ink, and anti-counterfeit label. Through combination of twisted conjugation core and donor and acceptor units, a luminogen (2-(bis(4-(carbazol-9-yl)phenyl)methylene)malononitrile (1) was synthesized. Luminogen 1 can form three kinds of crystals emitting green (1GC, λem = 506 nm, ΦF = 19.8%), yellow-green (1YC, λem = 537 nm, ΦF = 17.8%), and orange (1OC, λem = 585 nm, ΦF = 30.0%) light upon 365 nm UV illumination. The emission of amorphous solid of 1 (1Am) overlaps with that of 1OC (λem = 585 nm), with quantum yield of 13.9%, which is seldom reported. Emission of 1 can be switched among green, yellow-green, and orange through morphology modulation upon exposure to thermal, solvent vapor, or mechanical stimuli. Finally, its potential application in optical recording was also investigated.
Highlights
Stimuli responsive luminescent materials have attracted much attention in recent years due to their potential application in optical storage [1], optoelectronic devices [2,3,4], security papers [5], and sensor [6,7,8,9,10,11,12,13,14,15]
Their practical applications are limited because emissions of many luminogens are weakened or totally quenched in the solid state, which is known as aggregation-caused quenching (ACQ) [27,28]
In 2001, Tang found that a series of propeller-like luminogens were nearly nonemissive in solution but emitted intensely upon aggregation, Tang coined this phenomenon as aggregation-induced emission (AIE) [29,30]
Summary
Stimuli responsive luminescent materials have attracted much attention in recent years due to their potential application in optical storage [1], optoelectronic devices [2,3,4], security papers [5], and sensor [6,7,8,9,10,11,12,13,14,15]. The emission colors and intensities of these materials can be tuned by external stimuli, such as heat [16,17,18], solvent vapor [19,20,21], and mechanical perturbation (including grinding, shearing, smashing, or stretching) [22,23,24,25,26]. Their practical applications are limited because emissions of many luminogens are weakened or totally quenched in the solid state, which is known as aggregation-caused quenching (ACQ) [27,28]. The emission of many CIEE active luminogens can be switched between different states through morphological modulation [34,35,36]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
