Haider, G.G.HaiderHung-I LinKanchan YadavKun-Ching ShenYu-Ming LiaoHan-Wen HuPradip Kumar RoyKrishna Prasad BeraKung-Hsuan LinHsien-Ming LeeYit-Tsong ChenFu-Rong ChenYANG-FANG CHEN2019-12-272019-12-272018https://scholars.lib.ntu.edu.tw/handle/123456789/442976Production of multicolor or multiple wavelength lasers over the full visible-color spectrum from a single chip device has widespread applications, such as superbright solid-state lighting, color laser displays, light-based version of Wi-Fi (Li-Fi), and bioimaging, etc. However, designing such lasing devices remains a challenging issue owing to the material requirements for producing multicolor emissions and sophisticated design for producing laser action. Here we demonstrate a simple design and highly efficient single segment white random laser based on solution-processed NaYF 4 :Yb/Er/Tm@NaYF 4 :Eu core-shell nanoparticles assisted by Au/MoO 3 multilayer hyperbolic meta-materials. The multicolor lasing emitted from core-shell nanoparticles covering the red, green, and blue, simultaneously, can be greatly enhanced by the high photonic density of states with a suitable design of hyperbolic meta-materials, which enables decreasing the energy consumption of photon propagation. As a result, the energy upconversion emission is enhanced by ∼50 times with a drastic reduction of the lasing threshold. The multiple scatterings arising from the inherent nature of the disordered nanoparticle matrix provide a convenient way for the formation of closed feedback loops, which is beneficial for the coherent laser action. The experimental results were supported by the electromagnetic simulations derived from the finite-difference time-domain (FDTD) method. The approach shown here can greatly simplify the design of laser structures with color-tunable emissions, which can be extended to many other material systems. Together with the characteristics of angle free laser action, our device provides a promising solution toward the realization of many laser-based practical applications. Copyright © 2018 American Chemical Society.[SDGs]SDG7Coherent scattering; Color; Core shell nanoparticles; Display devices; Electromagnetic simulation; Energy utilization; Laser beams; Metamaterials; Shells (structures); Solid state lasers; Time domain analysis; Material requirements; Multi-color emissions; Multiple wavelengths; Photonic density of state; Random lasers; Single segments; Solid state lighting; Up conversion; Finite difference time domain methodjournal article10.1021/acsnano.8b030352-s2.0-85056089105https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056089105&doi=10.1021%2facsnano.8b03035&partnerID=40&md5=d0ab12b934f6795979fcb51e8b200461