Wide Range Near-Zero Thermal Quenching of Orange-Yellow Phosphor via Impeding Self-Oxidation of Eu for Versatile Optoelectronic Applications.

LiSrSiO:Eu is a promising substitute for traditional YAlO:Ce (YAG:Ce) owing to its strong orange-yellow emission of 4f-5d transition originating from Eu dopant, covering the more red-light region. However, its inevitable luminescence thermal quenching at high temperatures and the self-oxidation of Eu strongly impede their applications. Their remediation remains highly challenging. Herein, an anti-self-oxidation(ASO) concept of Eu in LiSrSiO substrate by adding trivalent rare-earth ions (A: 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 LiSrASiO:Eu with a wide range near-zero thermal quenching is obtained, superior to other Eu activated phosphors. The presence of A ions with various radii modifies the ASO degree of Eu 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 LiSrSiO:Eu in lighting and display fields.