Efficient and tuneable photoluminescent boehmite hybrid nanoplates lacking metal activator centres for single-phase white LEDs

• Published in: Nature communications 2014-12, Vol.5 (1), p.5702-5702, Article 5702
• Main Authors: Bai, Xue, Caputo, Gianvito, Hao, Zhendong, Freitas, Vânia T., Zhang, Jiahua, Longo, Ricardo L., Malta, Oscar L., Ferreira, Rute A.S., Pinna, Nicola
• Format: Article
• Language: English
• Subjects: 140/131; 639/301/1019/1020; 639/301/357; 639/766/25; Fourier transforms; Humanities and Social Sciences; Ligands; Light emitting diodes; multidisciplinary; Nanoparticles; Point defects; Science; Science (multidisciplinary); Temperature
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6702

White light-emitting diodes (WLEDs) are candidates to revolutionize the lighting industry towards energy efficient and environmental friendly lighting and displays. The current challenges in WLEDs encompass high luminous efficiency, chromatic stability, high colour-rending index and price competitiveness. Recently, the development of efficient and low-cost downconverting photoluminescent phosphors for ultraviolet/blue to white light conversion was highly investigated. Here we report a simple route to design high-efficient WLEDs by combining a commercial ultraviolet LED chip (InGaAsN, 390 nm) and boehmite (γ-AlOOH) hybrid nanoplates. Unusually high quantum yields ( η yield =38–58%) result from a synergic energy transfer between the boehmite-related states and the triplet states of the benzoate ligands bound to the surface of the nanoplates. The nanoplates with η yield =38% are able to emit white light with Commission International de l’Eclairage coordinates, colour-rendering index and correlated colour temperature values of (0.32, 0.33), 85.5 and 6,111 K, respectively; overwhelming state-of-the-art single-phase ultraviolet-pumped WLEDs phosphors. One approach to making white light LEDs is to combine a phosphor material that emits light over a wide spectrum with a ultraviolet LED. Xue Bai et al. demonstrate an inexpensive boehmite hybrid phosphor that produces high-quality white light with high efficiency.