Assessment of Crystalline Materials for Solid State Lighting Applications: Beyond the Rare Earth Elements

Abstract

<jats:p>In everyday life, we are continually exposed to different lighting systems, from the home interior to car lights and from public lighting to displays. The basic emission principles on which they are based range from the old incandescent lamps to the well-established compact fluorescent lamps (CFL) and to the more modern Light Emitting Diode (LEDs) that are dominating the actual market and also promise greater development in the coming years. In the LED technology, the key point is the electroluminescence material, but the fundamental role of proper phosphors is sometimes underestimated even when it is essential for an ideal color rendering. In this review, we analyze the main solid-state techniques for lighting applications, paying attention to the fundamental properties of phosphors to be successfully applied. Currently, the most widely used materials are based on rare-earth elements (REEs) whereas Ce:YAG represents the benchmark for white LEDs. However, there are several drawbacks to the REEs’ supply chain and several concerns from an environmental point of view. We analyze these critical issues and review alternative materials that can overcome their use. New compounds with reduced or totally REE free, quantum dots, metal–organic framework, and organic phosphors will be examined with reference to the current state-of-the-art.</jats:p>

Efficient dispersion of organic fluorophores by size matching with a new di-functionalized spacer interleaved into layered double hydoxide

“…The development and use of luminescent compounds containing rare-earth (RE) elements (europium, cerium, yttrium…) is currently predominant [2][3][4][5][6][7]. However, economic and environmental issues resulting from the exploitation of these RE elements [8][9][10][11] have made it a matter of concern for the European Union [12], thus encouraging the development of phosphors using other elements [2,[13][14][15]. To employ an organic luminescent dye such as Sulforhodamine B (SRB) is a good alternative.…”

Electrochemistry, Electrodeposition, and Photoluminescence of Eu (III)/Lanthanides (III) on Terpyridine-Functionalized Ti Nanospikes

“…Lanthanide (Ln) elements have very usefully appeared in diverse application fields such as display industry, magnets, bio industry, pyroprocessing technology in nuclear power plants, and energy/environment fields [1][2][3][4][5][6][7][8][9][10]. The Ln elements have very unique and similar physicochemical properties because of electronic configurations in 4f-block in the periodic table.…”

Photostimulated Defect Creation Processes in the Undoped and Bi3+‐Doped Ca3Ga2Ge3O12 Garnets

“…However, due to the relatively high cost and limited resources of rare earths, their high supply disruption risk, and the environmental issues related to their mining and refinement, these materials should be replaced by highly effective rare‐earth‐free compounds. Recently, these problems were analyzed in detail, and alternative materials suitable for various lighting applications were considered (see, e.g., Pavel et al and Ricci [ 14,15 ] and references therein).…”