Wide Range Near‐Zero Thermal Quenching of Orange–Yellow Phosphor via Impeding Self‐Oxidation of Eu2+ for Versatile Optoelectronic Applications

Abstract

AbstractLi2SrSiO4:Eu2+ is a promising substitute for traditional Y3Al5O12:Ce3+ (YAG:Ce3+) owing to its strong orange–yellow emission of 4f‐5d transition originating from Eu2+ dopant, covering the more red‐light region. However, its inevitable luminescence thermal quenching at high temperatures and the self‐oxidation of Eu2+ strongly impede their applications. Their remediation remains highly challenging. Herein, an anti‐self‐oxidation(ASO) concept of Eu2+ in Li2SrSiO4 substrate by adding trivalent rare‐earth ions (A3+: A = La, Gd, Y, Lu) for highly efficient and stable orange–yellow light emission have been proposed. A significantly increased orange–yellow emission (202% improvement) from Li2Sr0.95A0.05SiO4:Eu2+ with a wide range near‐zero thermal quenching is obtained, superior to other Eu2+ activated phosphors. The presence of A3+ ions with various radii modifies the ASO degree of Eu2+ ions, achieving the tunable chemical state, composition, electronic configuration, crystal‐field strength, and luminescent characteristics of the developed phosphors. For the proof of the concept, a W‐LED device and a PDMS (Polydimethylsiloxane) luminescent film are fabricated, endowing excellent luminescence performance and thermal stability and the huge application prospects of Li2SrSiO4:Eu2+ in lighting and display fields.