Solvent-Induced Self-Assembly of Copper Nanoclusters for White Light Emitting Diodes

Abstract

As a type of luminescent material, copper nanoclusters (Cu NCs) are widely concerned because of their low cost, nontoxicity, and outstanding biocompatibility. However, research studies on the preparation of hydrophobic Cu NCs with high quantum yield can be improved. In this work, we first synthesized atomically precise triphenylphosphine (PPh 3 )-capped Cu NCs (Cu 4 −NCs). Second, we adopted solvent engineering strategies to trigger the self-assembly of Cu 4 −NCs into the assembly with branched structures, thereby achieving aggregation-induced emission (AIE), thermally activated delayed fluorescence (TADF), and a high absolute quantum yield of 67.05%. Moreover, we performed structural characterization and optical analysis, which revealed that the high compactness of the assembly enhances the cuprophilic interaction and suppresses the intramolecular vibration and rotation of the Cu 4 −NCs ligand, protecting the Cu core from singlet oxygen quenching. These properties lead to the emergence of TADF and AIE. By mixing the as-assembled Cu 4 −NCs with commercial phosphors, a white light emitting diode prototype can be fabricated. This research demonstrates that TADF emission and the robust luminescence structure of the Cu 4 − NCs assembly provide them a high application value and extend the research opportunities for metal NCs in optical devices.

Bright and Photostable Fluorescent Metal Nanocluster Supraparticles from Invert Emulsions

“…The blend of AuNC‐SPs, AgNC‐SPs, CuNC‐SPs, and His‐AuNC‐SPs (at a mass ratio of 1 : 3 : 5 : 10) gives out a bright white light upon UV excitation, having CIE (International Commission on Illumination) color coordinates of (0.31, 0.32) and a color temperature of 6600 K (Figure 4). Reports have demonstrated the application of MNCs, by combining with other luminescent materials, in the white‐light‐emitting diodes (WLEDs) with different merits [23–25] . The blend of MNC‐SPs exhibits promise in fabricating WLED devices (the inset in Figure 4b), with enhanced PL properties as compared to discrete MNCs, high tunability potential of light color, and flexibility in device fabrication for desired performances.…”

“…Reports have demonstrated the application of MNCs, by combining with other luminescent materials, in the white-light-emitting diodes (WLEDs) with different merits. [23][24][25] The blend of MNC-SPs exhibits promise in fabricating WLED devices (the inset in Figure 4b), with enhanced PL properties as compared to discrete MNCs, high tunability potential of light color, and flexibility in device fabrication for desired performances.…”

Enhancing Proton Conductivity of Nafion Membrane by Incorporating Porous Tb-Metal–Organic Framework Modified with Nitro Groups

“…Metal–organic frameworks (MOFs) have attracted much attention because of their extensive applications. − Especially, more and more researchers are interested in MOFs as proton conductors in recent years. − In order to enhance the σ H+ of MOFs, researchers usually fill MOF pores with proton carriers, such as NH 4 + or H 2 O, as guest molecules, expecting to form rich hydrogen bond networks between guest molecules and host framework, providing pathways for proton conduction. The second strategy commonly used to improve MOF proton conductivities is to use substituents, such as −SO 3 H and −COOH, to modify rigid ligands, expecting to form hydrophilic channels and facilitate proton transfer .…”

Efficient One-Pot Synthesis of Bright Blue-Emitting Ce3+-Based Phosphor: Application for the Construction of Warm White-Light-Emitting Diodes and Anticounterfeiting

“…Meanwhile, blue light retinal injuries arising from a strong blue spike in the white-light spectrum prevents this technology from widespread applications. − To reduce light toxicity of the blue chip, an ultraviolet (UV)-LED chip is selected as the light source to excite a mixture of trichromatic [red-(R)/green-(G)/blue-(B)] phosphors for the construction of WLEDs. Diverse materials such as quantum dots, organic compounds, rare-earth metal-doped zeolites, and metal complexes have been synthesized for the construction of WLEDs. − Among the developed phosphors, lanthanide (Ln)-based materials have emerged as powerful building blocks for the effective preparation of full-color and white-light-emitting diodes thanks to their excellent sharp-emission luminescence properties with suitable sensitization. , Ln-based green and red phosphors have been extensively investigated because of their characteristics of easily sensitized luminescence. , However, it is hard to achieve Ln-based phosphors with blue emission, which remains a challenging task . To fabricate WLEDs, green-emitting and red-emitting Ln-based phosphors are usually codoped with other blue phosphors such as organic fluorophores, silicon nanoparticles, and quantum dots, , which might require different excitation wavelengths, limiting their potential applications in the light industry.…”