Green route synthesis of K2SiF6:Mn⁴⁺ red phosphor through a brief one-step co-precipitation method for warm white light LEDs

Using a green and convenient method to prepare fluoride red phosphor is an important challenge for industrialization applications. In this work, K2SiF6:Mn4+ red phosphor was successfully prepared through a brief one-step co-precipitation method without HF. A simplified and non-toxic ion exchange strategy for the formation of narrow-band red-emitting K2SiF6:Mn4+ phosphors was developed using different solvent (HAc, H3PO4, HNO3, HCl, H2O). The photoluminescence intensity of the prepared K2SiF6:Mn4+ red phosphor was the highest when the pH of the reaction solution was 1.0. Furthermore, using K2SiF6:Mn4+ as red component, the warm white light LED (light-emitting diode) with low correlated color temperature (CCT = 4095 K), high color rendering index (CRI, Ra = 87) was achieved, which proved that the phosphor synthesized by this method had great application potential. The preparation method provided in this article is safer and more environmentally friendly, and has important commercial and social value.