Small molecule-doped organic crystals towards long-persistent luminescence in water and air

Abstract

Organic long-persistent luminescence materials can be easy to quench in aqueous solutions or air, which limits their wide applications. Here we report novel doped organic crystals to overcome this challenge....

Anin situDNA content detection enabled by organic long-persistent luminescence materials with tunable afterglow-time in water and air

“…Combined with our previous research results that this type of doped-crystals can only release high-efficiency LPL emission when a high-quality and uniformly doped single-crystal structure is formed. 17,20 We reveal that the DPA : DDFx doping systems (x = y, p or none) with LPL properties require a high-quality single-crystal structure, in which the trace content doping has a significant effect on LPL performance, but has little effect on the crystal morphology of the DPA host matrix.…”

“…The first step is to use the structural differences of a few derivatives (as guest) to influence persistent-RTP of the host-immobilized host-guest doping crystal, thereby forming distinctly differentiated RTP lifetimes and LPL durations in water and air, from which we can easily screen out an appropriate LPL duration as the duration upper-limit for the second step. Then, the second step is to use the addition of the thirdparty material to affect persistent-RTP quenching to gradually tune LPL duration from the above upper-limit to 0 s. Specifically, we discovered that doping a trace amount of the guest 2,7-di-(N,N-diphenylamino)-9,9-dimethyl-9H-fluorene (DDF) into the small-molecule diphenylamine (DPA) as host matrix can induce a high-efficiency persistent-RTP effect in water and air, 17 then, we adopt a convenient and ''green'' doping method in air to obtain three organic crystalline materials DPA : DDFx (x = y, p or none) with differentiated LPL durations of 12 s, 2 s, and 8 s (Fig. 1), respectively, by adjusting charge separation efficiency between the DPA host matrix and the trace guest DDF derivatives (DDFx) to cause a significant persistent-RTP difference.…”

Highly Stable Metal‐Free Long‐Persistent Luminescent Copolymer for Low Flicker AC‐LEDs

“…[25] However, the trap filling process of these inorganic LPL phosphors usually requires a long irradiation time (> 30 s), [26] which cannot be synchronized with the ultrashort dimming time of AC-LEDs-based devices, resulting in insufficient compensation. [27] Thus, OLPL phosphors with both high initial LPL brightness [28] and fast filling speed [29] are required to fabricate high-quality AC-LEDs with low flicker.…”

Influence of Guest/Host Morphology on Room Temperature Phosphorescence Properties of Pure Organic Doped Systems

“…In recent years, the types of guest/host systems have been greatly developed, which mainly include a strong electron donor–acceptor system, , triphenylamine system, − phenylamine derivative system, − benzophenone system, − amide system, product-impurity system, , and some others. − Furthermore, the mechanism of the RTP phenomenon has been gradually explored, mainly including the host matrix restricting the motions of the guest molecules, , energy synergy between the guest and host molecules by forming a CT state , or excitons clusters, assisting the intersystem crossing of the guest excitons, ,,− Förster energy transfer, and Dexter energy transfer. , Researchers have noticed that the electronic properties and energy levels of the guest/host molecules have an important influence on the phosphorescence activities of the doped systems and generally believed that the phosphorescence of most doped systems is essentially emitted by the guest molecules themselves. − ,, However, in the established small molecule guest/host systems, two basic and important questions are often ignored: the existing form of the guest in the host matrix and the effect of the molecular morphology on the phosphorescence property (Scheme ). The two basic issues are closely related to the development of guest/host phosphorescence materials, the assumption of the luminescence mechanism, and the establishment of the calculation models, which urgently need to be investigated.…”

“…43,46 Researchers have noticed that the electronic properties and energy levels of the guest/host molecules have an important influence on the phosphorescence activities of the doped systems and generally believed that the phosphor-escence of most doped systems is essentially emitted by the guest molecules themselves. [26][27][28][29][30][31][32][33][34][35][36][37][38]44,46 However, in the established small molecule guest/host systems, two basic and important questions are often ignored: the existing form of the guest in the host matrix and the effect of the molecular morphology on the phosphorescence property (Scheme 1). The two basic issues are closely related to the development of guest/host phosphorescence materials, the assumption of the luminescence mechanism, and the establishment of the calculation models, which urgently need to be investigated.…”