Effects of using MgO, CaO additives as sintering aid in pressureless sintering of M2Si5N8:Eu2+ (M = Ba, Sr) phosphor ceramics for amber LED automotive applications

Phosphors have wide applications in many industries, especially the automotive industry. Low efficiency and complex production methods are current challenges of phosphor packaging technology. In this study, M2Si5N8:Eu2+ (M = Ba, Sr) phosphor ceramics (PCs) were developed that exhibited excellent thermal quenching characteristics and a broad wavelength range-580 (yellow)-620 nm (amber)-for use as automotive amber light-emitting diode (LED) light sources. Phosphors-M2Si5N8:Eu2+ (M = Ba, Sr)- with various Ba:Sr compositions were synthesized at 1600 degrees C. These phosphors were, in turn, used to fabricate PCs; pressureless sintering was aided by the addition of a MgO/CaO-70:30-mixture. The density, microstructure, and optical properties of the phosphors and PCs were analyzed. When the molar concentration of Sr was 0.2 mol, the corresponding phosphor wavelength was 593 nm; these optical characteristics are suitable for amber LED applications. The PC containing 5 wt% sintering aid showed a density of 4.187 g/cm(3) and relative density of more than 99%. These sintered PCs demonstrated excellent adaptive optical characteristics that can be used to great effect in automotive LED applications. (C) 2020 Elsevier B.V. All rights reserved.