Dual-emitting from Bi3+/Eu3+ co-activated akermanite phosphor for optical thermometric applications

Abstract

In this paper, Ca 2 MgSi 2 O 7 : Bi 3+ , Eu 3+ thermometric phosphors with dual-emitting centers were favorably designed. Phosphors were created by the approach of solid phase in high temperature condition. The inner phase structure and photoluminescence characteristics were investigated. The approaches of characterization including X-ray diffractometry, SEM, EDS mapping, ultraviolet–visible diffuse reflectance spectroscopy, as well as fluorescence spectrometry were applied. The influence of temperature on the photoluminescence characteristics of Ca 2 MgSi 2 O 7 : Bi 3+ , Eu 3+ phosphors was systematically researched. The intensity ratio of 3 P 1 → 1 S 0 purple luminescence of Bi 3+ and 5 D 0 → 7 F 2 red luminescence of Eu 3+ is dependent on the temperature, which provides a method of optical sensing thermometry. Under the UV excitation of 287 nm, the maximum relative sensitivity ( S r ) of this Ca 2 MgSi 2 O 7 : Bi 3+ , Eu 3+ phosphor is 0.66%K −1 (at 533 K) and absolute sensitivity ( S a ) gets to 0.0086 K −1 (at 573 K). The experimental phenomena were explained by the thermal-quenching mechanism. The garnered results provide an idea for the future development of luminescence intensity ratio (LIR) technology sensing materials on the basis of Ca 2 MgSi 2 O 7 . 1 The novel Ca2MgSi2O7: Bi3+, Eu3+ phosphors with dual-emitting centers were prepared by high-temperature solid-phase method in air. 2 The Ca2MgSi2O7: Bi3+, Eu3+ phosphors can circumvent the drawbacks of TCL-based phosphors. 3 The Ca2MgSi2O7: Bi3+, Eu3+ phosphors have high temperature sensitivity and signal discriminability. 4 The thermal-quenching mechanism of Bi3+ and Eu3+ were discussed.