Rapid synthesis of environmentally friendly submicron K2SiF6:Mn4+ phosphors: Advancing micro-LED technology

The development of light-emitting diode (LED) technology has intensified the requirements for the particle size of the K₂SiF₆:Mn⁴⁺ phosphor. However, the synthesis technology of the K₂SiF₆:Mn⁴⁺ phosphor possessing small particle sizes remains underdeveloped, rendering it difficult to fulfill the development requirements of display technology. This study presents an ammonium salt–assisted synthesis strategy for the rapid and hydrofluoric acid–free synthesis of submicron-sized K₂SiF₆:Mn⁴⁺, achieving an internal quantum yield of 98 % and average particle size of ∼ 200 nm. The synthesized material demonstrates excellent thermal stability, and its luminous intensity at 423 K is 136 % higher than that at 298 K, which is attributed to a negative thermal quenching effect. A high-performance white LED prepared using the as-developed material as the red-light-generation component exhibited a luminous efficacy of 113 lm/W and color rendering index of 93. Furthermore, the fluorescent inks developed using the prepared submicron phosphors can be utilized for screen printing. In summary, this study introduces a method for the ecofriendly, efficient, and cost-effective synthesis of submicron Mn⁴⁺-doped fluoride phosphors. Moreover, it presents a potential red fluorescent material for application in the development of full-color micro-LEDs.