Recent Advances on Host–Guest Material Systems toward Organic Room Temperature Phosphorescence

Abstract

The design and characterization of purely organic room‐temperature phosphorescent (RTP) materials for optoelectronic applications is currently the focus of research in the field of organic electronics. Particularly, with the merits of preparation controllability and modulation flexibility, host–guest material systems are encouraging candidates that can prepare high‐performance RTP materials. By regulating the interaction between host and guest molecules, it can effectively control the quantum efficiency, luminescent lifetime, and color of host–guest RTP materials, and even produce RTP emission with stimuli‐responsive features, holding tremendous potential in diverse applications such as encryption and anti‐counterfeiting, organic light‐emitting diodes, sensing, optical recording, etc. Here a roundup of rapid achievement in construction strategies, molecule systems, and diversity of applications of host–guest material systems is outlined. Intrinsic correlations between the molecular properties and a survey of recent significant advances in the development of host–guest RTP materials divided into three systems including rigid matrix, exciplex, and sensitization are presented. Providing an insightful understanding of host–guest RTP materials and offering a promising platform for high throughput screening of RTP systems with inherent advantages of simple material preparation, low‐cost, versatile resource, and controllably modulated properties for a wide range of applications is intended.

Manipulation of Triplet Excited States in Two‐Component Systems for High‐Performance Organic Afterglow Materials

“…In particular, the past several years have witnessed the exciting advancements of high-performance organic afterglow materials based on two-component design strategies. [13,15,38,[51][52][53][54][55][56][57] Two-component design strategies for RTP and afterglow material fabrication possess following advantages (Figure 2): first, the strategies allow very flexible choice of building blocks to construct RTP and afterglow materials; second, a series of RTP and afterglow materials with diverse chemical structures and compositions can be readily prepared with small synthetic efforts; third, in-depth and systematic studies can be performed by fixing one component and varying the other component, from which the underlying photophysics can be revealed to achieve high-performance afterglow materials; forth, if external physical stimuli, chemical or biological substances perturb the properties of either component, or the interactions between two components, the two-component afterglow materials can give rise to optical responses such as change of afterglow colors and afterglow durations which can be distinguished and recorded by human eyes and low-cost optical instruments. Based on this, it is envisaged that an intriguing and portable platform can be established for time-gated optical sensing, detection and imaging to avoid the interference of fluorescence backgrounds by taking advantage of the long emission lifetimes of afterglow materials; this portal platform using low-cost and portable equipment would function at hospital bedside, at home and even outdoors, rather than that only take place in well-equipped laboratory.…”

Halide-containing organic persistent luminescent materials for environmental sensing applications

“…Similarly, the flexible material design of doping systems makes it easy to realize colourful OPL emission by changing the guest molecules. 95,96 Remarkably, ultralong luminescence with emission lifetimes greater than 1 hour can be achieved in pure organic doping systems. 32,92,97–99 …”

Efficient and Color‐Tunable Dual‐Mode Afterglow from Large‐Area and Flexible Polymer‐Based Transparent Films for Anti‐Counterfeiting and Information Encryption

“…Because of these essential principles, heteroatoms, heavy‐halogen atoms, and carbonyl and sulfonyl groups have been reported to promote the spin‐orbit coupling (SOC) of organic luminophores [4] . In the meantime, various approaches are employed to suppress the molecular vibrational dissipations such as crystallization, host‐guest doping, and polymerization [1d, 5] . In the past few years, several ultralong organic phosphorescence (UOP) emitters with different emission colors have been developed [1d, 6] .…”

“…In the meantime, various approaches are employed to suppress the molecular vibrational dissipations such as crystallization, host‐guest doping, and polymerization [1d, 5] . In the past few years, several ultralong organic phosphorescence (UOP) emitters with different emission colors have been developed [1d, 6] . Although significant progress has been made in the field of UOP, organic materials with color‐tunable afterglow are still limited [1d, 6f, 7] .…”

“…In the past few years, several ultralong organic phosphorescence (UOP) emitters with different emission colors have been developed [1d, 6] . Although significant progress has been made in the field of UOP, organic materials with color‐tunable afterglow are still limited [1d, 6f, 7] . To date, only scattered examples have been reported to show different afterglow colors under external stimuli, and most of them are organic crystals [1f, 8] .…”