Learning from a Mineral Structure toward an Ultra-Narrow-Band Blue-Emitting Silicate Phosphor RbNa (Li SiO ) :Eu.

Learning from natural mineral structures is an efficient way to develop potential host lattices for applications in phosphor converted (pc)LEDs. A narrow-band blue-emitting silicate phosphor, RbNa (Li SiO ) :Eu (RNLSO:Eu ), was derived from the UCr C -type mineral model. The broad excitation spectrum (320-440 nm) indicates this phosphor can be well matched with the near ultraviolet (n-UV) LED chip. Owing to the UCr C -type highly condensed and rigid framework, RNLSO:Eu exhibits an extremely small Stokes shift and an unprecedented ultra-narrow (full-width at half-maximum, FWHM=22.4 nm) blue emission band (λ =471 nm) as well as excellent thermal stability (96 %@150 °C of the initial integrated intensity at 25 °C). The color gamut of the as-fabricated (pc)LEDs is 75 % NTSC for the application in liquid crystal displays from the prototype design of an n-UV LED chip and the narrow-band RNLSO:Eu (blue), β-SiAlON:Eu (green), and K SiF :Mn (red) components as RGB emitters.