Systematic Approach in Designing Rare-Earth-Free Hybrid Semiconductor Phosphors for General Lighting Applications

Abstract

As one of the most rapidly evolving branches of solid-state lighting technologies, light emitting diodes (LEDs) are gradually replacing conventional lighting sources due to their advantages in energy saving and environmental protection. At the present time, commercially available white light emitting diodes (WLEDs) are predominantly phosphor based (e.g., a yellow-emitting phosphor, such as cerium-doped yttrium aluminum garnet or (YAG):Ce(3+), coupled with a blue-emitting InGaN/GaN diode), which rely heavily on rare-earth (RE) metals. To avoid potential supply risks of these elements, we have developed an inorganic-organic hybrid phosphor family based on I-VII binary semiconductors. The hybrid phosphor materials are totally free of rare-earth metals. They can be synthesized by a simple, low-cost solution process and are easily scalable. Their band gap and emission energy, intensity, and color can be systematically tuned by incorporating ligands with suitable electronic properties. High quantum efficiency is achieved for some of these compounds. Such features make this group of materials promising candidates as alternative phosphors for use in general lighting devices.

Optical Properties of Hybrid Organic‐Inorganic Materials and their Applications

“…de inorganic hybrids (essentially siloxane-based ones) embedding organic dyes, with the formation of covalent (dye-bridged hybrids) or non-covalent (dye-doped hybrids) dye-matrix interactions, QDs, inorganic nanoparticles and Ln 3+ complexes. Hybrids with photochromic features will be discussed in Section 3, whereas hybrids for phosphors [39] and for luminescent coatings (based on organic dyes, [40] fluorine polymers, [41] cooper iodide clusters [42] and on Ln 3+ ions [43][44][45] ) were not reviewed in detail, being only addressed in the context of LEDs and LSCs, respectively.…”

“…The stability, biocompatibility, and quenching efficacy of this nanocomposite open a different perspective for cell imaging in different independent colors, sequentially and simultaneously. Despite the efforts of the scientists on developing multicolor photochromic systems, most of them are based on polymers, [39] single crystals [207] or organogels [209,210] containing organic moieties (no organic-inorganic hybrids), and they still present strong limitations for a real implementation in commercial devices.…”

A Family of Highly Efficient CuI-Based Lighting Phosphors Prepared by a Systematic, Bottom-up Synthetic Approach

“…For example, our previous investigations of one-dimensional (1D)-CuI(L) staircase-like chain structures showed that their internal quantum yields (IQY) are typically <40%, considerably lower than those of RE-based commercial phosphors (>70%). 7,39 Additionally, reactions often yield mixture phases containing different CuI modules. Therefore, developing a fully controllable synthesis to attain target structures with significantly improved IQYs has been the main focus of our most recent study.…”

Syntheses, structures and tunable luminescence of lanthanide metal-organic frameworks based on azole-containing carboxylic acid ligand

“…For decades, many solid state materials have been explored and developed as white light emitting sources. These include inorganic oxide, inorganic quantum dots, nitride, organic molecules, polymers, and metal complexes [4][5][6][7][8][9][10][11][12]. Common approaches, such as dichromatic, tri-chromatic, and tetra-chromatic methods are often used to generate white light [13][14][15].…”