Work

Dual-mode emission optical temperature sensor and white light-emitting diodes using Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ phosphors regulated by cation-controlled crystal fields

Year: 2024

Type: article

Abstract: Efficient and environmentally friendly warm white light sources, along with non-contact optical temperature sensors, are currently at the forefront of luminescence research. Silicate-based phosphors have emerged as leading candidates in photonic material studies due to their outstanding thermal stability and tunable luminescence properties. In this investigation, we introduce a novel synthetic method that employs strategic cation substitution with Ba, Mg, Lu, and Sc to engineer a full-spectrum warm white light-emitting Ca2Y8Si6O26:Bi3+ phosphor. This approach not only enhances luminescence efficiency but also integrates a red component via Eu3+ doping, enabling single-component warm white light emission and facilitating non-contact optical temperature sensing.Our findings identify the optimal doping concentration for the Ca2Y8-8xSi6O26:Bi3+(x=0.005, 0.01, 0.03, 0.05, 0.1) phosphors series as 0.24 mol%. Synthesized phosphors exhibit a maximum excitation wavelength of 332 nm, with an optimal emission peak at 499 nm. Cations Ba2+ and Mg2+ significantly enhance the crystal structure and improve the emission intensity of Bi3+ ions. Performance assessments of both single-mode and dual-mode emission temperature sensors reveal Sa and Sr values of 0.012% and 0.0032 for the Ca2Y7.76Si6O26:0.24Bi3+ phosphor, respectively, with the Mg2+-doped variant further elevating the Sr value.For the dual-mode emission temperature sensor employing the Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ phosphor, Sa and Sr values based on the 499 nm and 422 nm emission peaks are measured at 0.006% and 0.0077, respectively, while the values for the 618 nm and 422 nm peaks are 0.029 and 0.0005. Additionally, the luminescence quality of the prepared phosphors was assessed using color coordinates, indicating that doping with higher concentrations of Eu3+ in Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ leads to a shift in emission towards the warm white light region.These results suggest that the Ca2Mg0.01Y7.73Si6O26:0.24Bi3+, 0.02Eu3+ and Eu3+ phosphors, synthesized through cation substitution and red light-emitting center incorporation, possess significant potential for applications in single-component warm white LEDs and non-contact optical temperature sensors.

Source: Journal of Alloys and Compounds

DOI: 10.1016/j.jallcom.2024.177824