Efficient narrow-band green phosphors for mini-LED displays using dual strategies of high concentration quenching and energy transfer

Abstract

Narrow-band green phosphors play an important role in displays. Through energy transfer from Eu²⁺ to Mn²⁺ and high concentration quenching of Mn²⁺ in GdMgAl₁₁O₁₉(GMAO), the quantum efficiency of GMAO:Mn²⁺ is enhanced from 26% to 45%. In GMAO, Mn²⁺ ions show a narrow green emission with a half-width at half-maximum (FWHM) of 27 nm. The energy transfer mechanism between Eu²⁺ and Mn²⁺ in GMAO is ascribed to the quadrupole–quadrupole interaction. The energy transfer efficiency of this series of phosphors can reach 76.64%. By combining GMAO:0.07Eu²⁺,0.7Mn²⁺,K₂SiF₆ (KSF):Mn⁴⁺, and BaMgAl₁₀O₁₇ (BAM):Eu²⁺ with an LED chip, a white light-emitting diode (WLED) that achieves a color gamut of up to 110% National Television System Committee (NTSC) and a luminous efficacy of up to 53.27 lm W⁻¹ is constructed. In addition, a uniform green luminescent array with a pixel size of 20 μm × 40 μm is obtained using GMAO:0.07Eu²⁺,0.7Mn²⁺. These results indicate that this series of phosphors have potential application in Mini-LED displays.