Respiration‐Responsive Colorful Room‐Temperature Phosphorescent Materials and Assembly‐Induced Phosphorescence Enhancement Strategies

Abstract

mechanical properties, good processing properties, ease of chemical modification, and easy preparation processes. [6][7][8][9] It is clear from the Jablonski diagram that to achieve phosphorescence emission, we can follow two approaches. One is to promote the S 1 → T n intersystem crossing. [10] The second is to suppress the nonradiative relaxation processes. Traditionally, organic molecules cannot emit phosphorescence at room temperature due to their inherently weak spin-orbit coupling, which means that excitons cannot efficiently span single and triplet states. [11] Therefore, it is often necessary to create strong intermolecular interactions to build a rigid network structure to enable phosphorescence generation and enhancement at room temperature. It is still a difficult task to build a non-toxic, non-hazardous, environmentally friendly, room-temperature phosphorescent material that can achieve colorful and long lifetimes. Most natural polymers are biocompatible, environmentally friendly, and non-toxic. Therefore, it is essential to explore more natural polymers with RTP properties that can be used to construct RTP emitting materials with long lifetimes. Usually, in order to obtain longer-lived and more-efficient phosphorescence emissions, researchers increase the inter-system scattering rate by introducing heavy atoms to increase the spin-orbit coupling between single and triplet states [12] or by cross-linking and polymerizing to produce a rigid environment to suppress non-radiative transitions. [13] Actually, several macrocycles, such as cyclodextrin and cucurbituril, have been used to tune phosphorescent characteristics. [14] Most of these only show adjustability in solution, reports on tunable RTP in the solid state are scarce.There is an increasing interest in stimulus-responsive luminescent materials that can undergo physical or chemical changes in response to external stimuli, such as mechanical forces, light, PH, and heat, due to the possible applications of such materials in the fields of lighting and display, optoelectronic devices, data storage, anti-counterfeiting, bio-imaging, and sensing. [15][16][17][18][19][20][21] To date, most of the stimulus-responsive luminescent materials have been based on fluorescence. [22][23][24] Compared with fluorescence emission, phosphorescence emission

Ultralong Organic Phosphorescence of Triazatruxene Derivatives for Dynamic Data Encryption and Anti‐counterfeiting

“…All organic room temperature phosphorescence (RTP) luminogens have drawn extensive attentions and shown intelligent potentials in the field of optoelectronic devices, [ 1‐3 ] sensor, [ 4‐5 ] information storage, [ 6‐10 ] biological imaging, [ 11‐13 ] and anti‐counterfeiting. [ 14‐16 ] Generally, organic luminogens in a single component seldom exhibit persistent phosphorescence at ambient conditions due to their intrinsic spin‐forbidden intersystem crossing (ISC) from the lowest single state (S 1 ) to the triplet state (T n ) as well as their ultrafast triplet exciton deactivation.…”

Photo-activated time-dependent color-changeable ultralong organic room temperature phosphorescence by co-doping strategy

“…[32][33][34][35] Stimulus-responsive color-changeable luminescent organic materials have attracted considerable attention in the past few years, especially for color-changeable UORTP materials. [36][37][38][39] According to our previous work, 27,[29][30][31] different phosphorescence units feature different phosphorescence lifetimes and different phosphorescence colors. Furthermore, there exist more variables in guest-matrix doping phosphorescence systems compared with single-component systems, [40][41][42] which offers more methods to tune the phosphorescence properties.…”

Organic room temperature phosphorescence enhancement by grinding and adding water for humidity detection and anti-counterfeiting printing

“…To this end, a number of stimulus-responsive RTP materials have been developed that can alter the emission intensity, afterglow lifetime and emission color by external stimuli. [17][18][19][20][21][22] Much effort has been made in searching for RTP materials, while most pure organic RTP materials exhibit phosphorescence only in their solid state, which impedes the practical applications of these phosphorescent materials. [23][24][25] The phosphorescence is always quenched in the presence of water due to the presence of dissolved oxygen.…”