Synthesis of UV/blue light-emitting aluminum hydroxide with oxygen vacancy and their application to electrically driven light-emitting diodes

• Published in: RSC advances Vol. 12; no. 7; pp. 4322 - 4328
• Main Authors: Lee, Heejae, Hong, Ahyoung, Kwak, Jeonghun, Lee, Seonghoon
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 28.01.2022; The Royal Society of Chemistry
• Subjects: Aluminum; Aluminum hydroxide; Carbonyls; Chemistry; Defects; Display devices; Emissivity; Hydroxides; Light; Light emission; Light emitting diodes; Low temperature; Nanoparticles; Oleic acid; Optoelectronic devices; Oxygen; Phosphors; Quantum efficiency; Rare earth elements; Reaction time; Toxicity; Zinc oxide
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra07942e

Aluminum hydroxide nanoparticles, one of the essential luminescent materials for display technology, bio-imaging, and sensors due to their non-toxicity, affordable pricing, and rare-earth-free phosphors, are synthesized via a simple method at a reaction time of 10 min at a low temperature of 200 °C. By controlling the precursor's ratio of aluminum acetylacetonate to oleic acid, UV or blue light-emitting aluminum hydroxides with oxygen defects and carbonyl radicals can be synthesized. As a result, aluminum hydroxide (Al(OH) 3− x ) nanoparticles overwhelmingly emit UVA light (390 nm) because of the oxygen defects in nanoparticles, and carbon-related radicals on the nanoparticles are responsible for the blue-light emission at 465 nm. Electrically driven light-emitting devices are applied using luminescent aluminum hydroxide as an emissive layer, that consists of a cost-efficient inverted bottom-emission structure as [ITO (cathode)/ZnO/emissive layers/2,2′-bis(4-(carbazol-9-yl)phenyl)-biphenyl (BCBP)/MoO 3 /Al (anode)]. The device with aluminum hydroxide as an emissive layer shows a maximum luminance of 215.48 cd m −2 and external quantum efficiency (EQE) of 0.12%. The new method for synthesizing UV-blue emitting aluminum hydroxides and their application to LEDs will contribute to developing the field of non-toxic optoelectronic material or UV-blue emitting devices. Ultraviolet/blue light-emitting aluminum hydroxide nanoparticles are prepared using a simple method and applied to the electrically driven light-emitting diode as an emissive layer.