Small Particle Size K ₂ SiF ₆ :Mn ⁴⁺ Phosphor for Micro-LEDs

The modern-day pc-LEDs for general illumination are based on a blue-emitting InGaN chip coated with a blend of two phosphors, a green-yellow Cerium-doped garnet phosphor and a red phosphor which is required to induce a “warm-white” color temperature (2700–3500 K). To achieve a preferred color rendering and energy efficiency, a red phosphor with narrow emission is ideal. For display applications with wide-color-gamut performance, white light LEDs composed of narrow emission in blue, green, and red are required and often achieved with pc-LEDs using a blue-emitting InGaN chip coated with a blend of two phosphors, a narrow green Europium-doped phosphor and a narrow red phosphor. One narrow red phosphor used in white light pc-LEDs that exceeds in the key performance requirements of a red emitter for both general illumination and display application is K 2 SiF 6 :Mn 4+ (PFS/KSF) phosphor [1-3]. This is attributable to its unique peak wavelength and narrow emission. Current Chemicals manufactures K 2 SiF 6 :Mn 4+ phosphor and sells it under the trade name, TriGain ® . TriGain ® phosphor has a typical median particle size of 20-40mm as well as some specialty versions with median particle size of 5-10mm. Recently, we have developed K 2 SiF 6 :Mn 4+ phosphor with a smaller particle size (1-3mm), optimized for next generation micro-LED displays such as TV, laptops, mobile phone (Fig. 1). This presentation will focus on the synthesis and optical properties of this new phosphor. We will compare the temperature dependence of the Mn 4+ luminescence and lifetime with that of the TriGain ® phosphor. The thermal quenching behavior is analyzed and discussed. This comparative study highlights the factors influencing non-radiative relaxation processes, which are fundamental to the understanding of phosphor quantum efficiency and performance. Figure 1