Enhanced upconversion luminescence and temperature sensing performance in Er3+/Yb3+-codoped K3ScF6 phosphors induced by tridoping with Bi3+ions

Herein, K3ScF6 upconversion luminescence (UCL) phosphors codoped with fixed Er3+, Yb3+ and various Bi3+- concentrations were prepared by solid-state reaction method. Phase and structure analysis indicate that the prepared samples belong to a cubic system and exhibit the shift in peaks position due to Bi3+ions doping. The upconversion (UC) emission properties of K3ScF6:Er3+/Yb3+/Bi3+ are investigated in detail. The UC emission intensity can be enhanced via tridoping with Bi3+ ions under 980 nm laser diode (LD) excitation. Changes in Bi3+ concentration and power density generate color tunability from green to red. Similarly, the CCT value changes from cool light to warm light. The fluorescence intensity ratio (FIR) technique based on Er3+ thermal coupling level (TCLs) was used to study the temperature sensing performance, the relative sensitivity (SR) of K3ScF6:0.05Er3+/0.15Yb3+/0.10Bi3+ reaches a maximum of 0.0174 K-1 at 298 K. This in-dicates that K3ScF6:Er3+/Yb3+/Bi3+ phosphors have potential applications in non-contact optical temperature sensors and color tunable devices.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Herein, K3ScF6 upconversion luminescence (UCL) phosphors codoped with fixed Er3+, Yb3+ and various Bi3+-concentrations were prepared, and their upconversion emission properties and temperature sensing performance were investigated. The results showed that tridoping with Bi3+ ions can enhance the upconversion emission intensity, and changes in Bi3+ concentration and power density can achieve color tunability and CCT value changes. Therefore, these phosphors have potential applications in non-contact optical temperature sensors and color tunable devices.