Ultra-Narrow-Band Blue-Emitting Oxoberyllates AELi(2)[Be4O6]:Eu2+ (AE=Sr,Ba) Paving the Way to Efficient RGB pc-LEDs

摘要

Highly efficient phosphor-converted light-emitting diodes (pc-LEDs) are popular in lighting and high-tech electronics applications. The main goals of present LED research are increasing light quality, preserving color point stability and reducing energy consumption. For those purposes excellent phosphors in all spectral regions are required. Here, we report on ultra-narrow band blue emitting oxoberyllates AELi(2)[Be4O6]:Eu2+ (AE=Sr,Ba) exhibiting a rigid covalent network isotypic to the nitridoalumosilicate BaLi2[(Al2Si2)N-6]:Eu2+. The oxoberyllates' extremely small Stokes shift and unprecedented ultra-narrow band blue emission with fwhm approximate to 25nm (approximate to 1200cm(-1)) at (em)=454-456nm result from its rigid, highly condensed tetrahedra network. AELi(2)[Be4O6]:Eu2+ allows for using short-wavelength blue LEDs ((em)440nm) for efficient excitation of the ultra-narrow band blue phosphor, for application in violet pumped white RGB phosphor LEDs with improved color point stability, excellent color rendering, and high energy efficiency.