Multicolor Persistent Luminescence for High-Sensitivity Optical Temperature Sensing, Human Motion Detection, and...

Area of Science:

• Materials Science
• Solid-State Chemistry
• Luminescence

Background:

• Multimodal luminescent materials are crucial for applications like noncontact temperature sensors and anticounterfeiting due to their dynamic luminescence and rapid optical response.
• Existing materials often require specific doping strategies to achieve desired multimodal optical functionalities.

Purpose of the Study:

• To synthesize and characterize novel multimodal luminescent phosphors based on CaYGaO4 doped with Bi3+, Eu3+, and Er3+.
• To investigate the down-conversion, up-conversion, long persistent, and mechanical luminescence properties of these materials.
• To explore their potential applications in anticounterfeiting, temperature sensing, and human motion detection.

Main Methods:

• High-temperature solid-state synthesis method was employed to prepare CaYGaO4: Bi3+, Eu3+/Er3+ phosphors.
• Comprehensive photoluminescence spectroscopy was used to analyze down-conversion, up-conversion, and long persistent luminescence.
• Mechanical luminescence and temperature-dependent luminescence were studied; density functional theory (DFT) and electron localization function (ELF) analysis were performed.

Main Results:

• Synthesized CaYGaO4 phosphors doped with Bi3+, Eu3+, and Er3+ exhibited multicolor luminescence, including down-conversion, up-conversion, long persistent, and mechanical luminescence.
• The CaY0.92GaO4: 0.01 Bi3+, 0.07Eu3+ phosphor demonstrated a maximum relative sensitivity of 1.49% K-1 for temperature sensing.
• DFT calculations revealed that ion doping reduces the band gap and induces the Jahn-Teller effect, facilitating carrier release and enhancing optical performance.

Conclusions:

• The developed CaYGaO4: Bi3+, Eu3+/Er3+ phosphors are effective multimodal luminescent materials with potential for static-dynamic anticounterfeiting.
• These materials offer a new avenue for developing advanced optical detection devices, including temperature sensors and human motion detectors.
• The stable defect states in these multimodal luminescent materials underpin their utility in information storage and security applications.