Multi-site occupancies and photoluminescence characteristics in developed Eu2+-activated Ba5SiO4Cl6 bifunctional platform: Towards manufacturable optical thermometer and indoor illumination.

Eu2+-activated Ba 5 SiO 4 Cl 6 phosphors with blue and green emissions were synthesized by a solid-state reaction route in a reduction atmosphere. The obtained crystal structure and photoluminescent properties indicated that three various Ba2+ ions sites were partially occupied by the Eu2+ ions. The optimal doping content for Eu2+ ions in the Ba 5 SiO 4 Cl 6 system was 5 mol%. The electric dipole-dipole interaction was attributed to the involved concentration quenching effect. The thermal resistance performance was identified by using the temperature-dependent emission spectra. Importantly, the internal quantum efficiency of the established final products reached up to 50.8%. Through utilizing the diverse sensitivities of blue and green emissions from Eu2+ ions to the temperature, a neoteric optical thermometer with a high absolute and relative sensor sensitivity of 0.031 K-1 and 0.87% K−1, respectively, at 498 K was achieved. By integrating the resultant cyan phosphors, commercial CaAlSiN 3 :Eu2+ red phosphors and a near-ultraviolet chip, the warm white light-emitting diodes with admirable colorific properties were integrated and manufactured. The complementary results elaborate that the Eu2+-activated Ba 5 SiO 4 Cl 6 phosphors are bifunctional platforms for both optical thermometer and indoor illumination. • The resultant phosphors exhibited visible cyan emission when excited at 397 nm. • The dipole-dipole interaction contributed to the concentration quenching mechanism. • The resultant phosphors possessed good thermal stability and high quantum efficiency. • The Sa and Sr values of the products was 0.031 K−1 and. • The LED lamp emitted brightness white light with superior photoelectric properties. [ABSTRACT FROM AUTHOR]