HF-Free Preparation, High Thermal and Color Stability of Mn 4+ Activated K 2 TiF 6 Red Phosphors for White Light-Emitting Diodes

Abstract

© The Author(s) 2017. Published by ECS. Mn4+activated fluoride phosphors have been considered as highly promising red component for warm white light-emitting diodes in recent years. In this paper, we successfully prepared the K2TiF6: Mn4+red phosphors in H3PO4/KHF2 liquid instead of the hypertoxic HF liquid. The impact factors, such as the amount of F source, the reaction temperature, reaction time, and the luminescence mechanism are investigated in detail. We found that K2TiF6: Mn4+shows pure red emission and can be excited by blue lights, which can perfectly match the InGaN chip based white light-emitting diodes. Most importantly, K2TiF6: Mn4+exhibits excellent quenching behavior and shows small color shift in the temperature range of 300-475 K. Our researches could provide a green synthetic strategy to obtain the K2TiF6: Mn4+phosphors and contribute to the optimization of red phosphors for white light-emitting diodes.