Upconversion Nano-Composites for Orthogonal Trichromatic Luminescence Aiming at High Color Purity Volume Display

Orthogonal three-color luminescence materials designed based on lanthanide doping multi-component nano-systems have exhibited great potential in volume display technology. Previous studies devoted to integrate the different color emitters within a single core-shell nanoparticle, which suffers complexity in synthesis and difficulty in repeatability. In this work, an alternative is proposed. Three kinds of upconversion nanocrystals (UCNCs) with relatively simple configurations are prepared separately. Each kind of nanocrystals takes charge of emit a specific color upon one particular excitation (i.e., 808, 980, and 1540 nm pumps). Luminescent property of the mixture containing these nanocrystals are investigated. Excitation wavelength driven orthogonal three-color luminescence property is found in this mixture. With the combination excitation, the emission color can be modulated, covering a gamut with its aera of 110% sRGB, superior to the previous reports. In addition, a quantized strategy to evaluate the orthogonality of the luminescence is also proposed, which will be useful for the further investigation and development of remote-type controlled luminescent materials. Finally, the demonstration of colored 3D display application is conducted and presented in this work. An approach to construct flexible 3D color display screen is proposed: first, three kinds of upconversion core-shell nanocrystals are synthesized, separately; then they are mixed and sealed to form an orthogonal trichromatic luminescent screen. A large color gamut (110% sRGB) is achieved, which is superior to the previous reports. image