Encapsulating Organic Dyes in Metal–Organic Frameworks for Color-Tunable and High-Efficiency White-Light-Emitting Properties

Abstract

The design of white-light phosphor is highly desirable for practical applications in SSL (solid-state lighting) and its related fields. Dye-loaded metal−organic frameworks (MOFs) have been widely demonstrated as one type of promising down conversion materials for WLEDs (white-light-emitting diodes), but two issues (dye leakage and inadequate quantum efficiency) require to be addressed before possible applications. Here, a series of single-phase dyes@In-MOF phosphors have been prepared in two different ways: the in-situ process and soaking method. The study of these dyes@In-MOF phosphors confirms the importance of this in-situ process that could effectively increase dye loading and quantum efficiency and greatly decrease dye leakage. As a result, a perfect WLED, fabricated using the in-situsynthesized (AF/RhB@In-MOF)-3 (AF: Acriflavine; RhB: Rhodamine B) and 450 nm blue LED chip, exhibited a very high quantum yield (QY, up to 42.27%), a high luminous efficacy (LE) of 50.75 lm/W, a high color rendering index (CRI) of 91.2, and nearly identical Commission International ed'Eclairage (CIE) coordinates (0.33,0.31), indicating the potential application of the dye-loaded MOFs with good color quality in smart white LEDs.

Luminescent Guests Encapsulated in Metal–Organic Frameworks for Portable Fluorescence Sensor and Visual Detection Applications: A Review

“…By using in situ encapsulation and seed-mediated synthesis to build a multilayer ZIF-8@dye@ZIF-8@dye, two types of size-matched dyes (perylene and rhodamine B) were included within the readily available ZIF-8 [ 60 ] ( Figure 3 A). Xu et al, fabricated a variety of single-phase dyes@In-MOF phosphors in situ, and the study significantly increased dye loading and quantum efficiency, while significantly reducing dye leakage [ 61 ] ( Figure 3 B). Yi et al, used a simple one-pot in situ selective self-assembly synthesis method, to effectively synthesize carbon dot (CD)-chelated Eu-MOFs, as dual-emission ratiometric fluorescence (RF) probes.…”

“…( F ) Photographs of samples exposed to sunlight (up) and under UV light (bottom). Reproduced with permission from [ 60 , 61 , 62 , 64 ]. Copyright 2022, Royal Society of Chemistry; 2022, American Chemical Society; 2020, Elsevier; and 2019, Elsevier.…”

Numerical Recognition System and Ultrasensitive Fluorescence Sensing Platform for Al3+ and UO22+ Based on Ln (III)-Functionalized MOF-808 via Thiodiglycolic Acid Intermediates

“…However, most of them face complex operation, high detection limits, poor selectivity, and other problems. , Moreover, taking economy and accuracy as well as sensitivity into account, analytical methods including ICP-MS, FAAS, and XRF can only be conducted in laboratories. , In comparison, fluorescence sensors have aroused wide attention during the past several decades owing to their significant advantages, especially low cost and high sensitivity. Noticeably, a variety of materials such as small molecules, carbon quantum dots, , and luminescent metal–organic frameworks (LMOFs) − have also been developed as fluorescent probes to monitor the content of metal cations. Among them, LMOFs are one of the most popular materials, fueled by their outstanding reusability and good stability in aqueous solution.…”

Tunable White Light Emission of a Metal–Organic Framework Based on a Bisquinoxaline Derivative by Introducing Red–Green Cationic Dyes

“…Considering the economic factors and preparation technology, traditional lighting sources often use the strategy of LED chips to excite phosphor to prepare WLEDs. − For example, ultraviolet LED chips coated with red, green, and blue phosphors can be prepared into WLEDs, whose color rendering index (CRI) can reach a very high level. However, there are still disadvantages, such as poor color stability, low reproducibility, and large color differences. , …”

“…However, there are still disadvantages, such as poor color stability, low reproducibility, and large color differences. 4,5 Additionally, most of the currently used phosphors contain rare earth elements such as Ce, Y, and Eu. As the demand for LED lamps increases dramatically, so does the demand for rareearth-based phosphors.…”