Highly efficient and thermally stable broadband green-emitting BaY2Sc2Al2SiO12:Ce3+ phosphors enabling warm-white LEDs with both high luminous efficacy and high color rendering index

Abstract

Exploring high-efficient broadband green phosphors that match the eye’s natural perception to produce light-emitting diodes (LED) with the vivid color reproduction and exceptional saturated colors is highly desired. Here, a bright green luminescence is revealed in an all-inorganic singly-phase Ce3+-activated broadband garnet-type BaY2Sc2Al2SiO12 (BYSASO:Ce3+) phosphor. Under a 439 nm InGaN-based blue LED chip irradiation, the representative BYSASO:3%Ce3+ sample showing a suitable green-emitting with the maximum emission peak position located at 532 nm and an impressive full width at half-maximum (FWHM) of 125 nm is presented, which can cover more cyan gap without sacrificing the green components. High quantum efficiency (IQE = 80.1%), outstanding thermal resistance behavior (73.9%@423 K) and color stability, as well as an appropriate CIE color coordinates of (0.3700, 0.5394) make this excellent optical material suitable for industrial application. Finally, a prototype warm white LED device, with proposed green-emitting BYSASO:3%Ce3+ phosphor and commercial (Ca,Sr)AlSiN3:Eu2+ as red phosphor upon blue chip excitation exhibits an extraordinary optical properties with satisfactory Ra of 93.3 and comfortable CCT of 3958 K, as well as an excellent luminous efficacy of 105.3 lm W-1. The resulting indicate that green-emitting BYSASO:Ce3+ garnet phosphor features the remarkable potential serving as a conversion material for high-quality illumination.