Regulation of β-Sialon and KSF Phosphors in Mini-LED Backlight

Mini-LED backlight technology has become the core solution for high-end displays due to its high contrast and wide color gamut characteristics. In this paper, we propose a Mini-LED backlighting technology based on the synergistic ratio of KSF red powder (K2SiF6:Mn⁴⁺) and β-Sialon green powder (Si6-zAl2O7N8-z:Eu²⁺) synergistically proportioned Mini-LED backlighting technology, this paper addresses the problems of limited color gamut (NTSC<85%), temperature drift (red light drift>1nm) and high scattering loss due to the broad spectral characteristics of traditional silicate phosphors. Through comparative experiments, it is found that the optimization of the red-to-green irradiance ratio can effectively suppress the competing absorption and red light scattering paths in the spectral overlap region (450-460nm) when the mass ratio of red-to-green phosphor is 2.5:1, achieving a luminous efficacy of 104.55lm/W and neutral white coordinates (x=0.33, y=0.37). Combined with the structural stability of hexagonal-phase β-Sialon and cubic-phase KSF verified by XRD, the system showed a red wavelength drift of <0.1nm, a color drift rate of <0.5%, and a color rendering index of Ra=74.3 after aging at 60°C for 500h. It was demonstrated that by the particle size modulation (β-Sialon D50=8μm) with Mn⁴⁺ strong crystal field effect (²Eg → ⁴A2g jump), the synergistic effect of particle size modulation (β-Sialon D50=8 μm) and Mn⁴⁺ strong crystal field effect (²Eg→⁴A2g jump), which can break through the bottleneck of the red-light proportion in the traditional 3:1 ratios (> 55%) and the color drift rate > 1.2%, and provide a new opportunity for the high-dynamic dimming suitability of Mini-LED backlighting (0Hz flicker-free) and ergonomic requirements, providing an innovative solution with high color gamut, low power consumption and thermal stability.