Deep red fluoride dots-in-nanoparticles for high color quality micro white light-emitting diodes
Doan Thi Tuyet, Thi Hong Quan Vu, Bartosz Bondzior, P.J. Dereń, Ravi Teja Velpula, Hieu Pham Trung Nguyen, Luu Anh Tuyen, Nguyễn Quang Hưng, Hoang‐Duy Nguyen
Abstract
In this study, a novel nanostructure of fluoride red emitting phosphor is synthesized via soft templates. K 2 SiF 6 :Mn 4+ nanocrystals in the range of 3-5 nm diameter are found inside the porous K 2 SiF 6 :Mn 4+ nanoparticle hosts, forming unique dots-in-nanoparticles (d-NPs) structures with controlled optical properties. The porous K 2 SiF 6 :Mn 4+ d-NPs exhibit a sharp and deep red emission with an excellent quantum yield of ∼95.9%, and ultra-high color purity with the corresponding x and y in the CIE chromaticity coordinates are 0.7102 and 0.2870, respectively. Moreover, this nanophosphor possesses good thermal stability in range of 300 K–500 K, under light excitation of 455 nm. The K 2 SiF 6 :Mn 4+ d-NPs are covered onto a surface of 100×100 µm 2 blue-yellow In x Ga 1−x N nanowire light-emitting diode (LED) to make warm white LEDs (WLEDs). The fabricated WLEDs present an excellent color rendering index of ∼95.4 and a low correlated color temperature of ∼3649 K. Porous K 2 SiF 6 :Mn 4+ d-NPs are suggested as a potential red component for high color quality micro WLED applications.