Precisely Modulating Oxygen Vacancies Via Heterovalent Ions Substitution in Spinel-Structured Phosphor for Versatile...

Area of Science:

• Materials Science
• Solid State Chemistry
• Luminescence

Background:

• Rare-earth ion-doped phosphors are crucial for optoelectronics.
• Atom vacancies in phosphors, caused by doping, pose challenges for optical applications.
• Controlling defect concentration is vital for phosphor performance.

Purpose of the Study:

• To accurately modulate oxygen vacancies in spinel-like ZnGa2O4 phosphors using Europium (Eu3+) doping.
• To explore the potential of these phosphors for advanced temperature sensing and optical information encryption.

Main Methods:

• Heterovalent substitution and ion radii differences were considered.
• Eu3+ doping was employed to introduce and control oxygen vacancies.
• First-principle calculations and experimental results were used to analyze defect states and luminescence properties.

Main Results:

• Increased Eu3+ doping led to a higher concentration of oxygen vacancies in ZnGa2O4.
• Deeper and wider electronic bandgap defect states were observed, enhancing afterglow emission.
• The phosphor exhibited excellent temperature sensing with a maximum relative sensitivity of 5.96% K−1 at 360 K.
• Successful demonstration of dynamic information encryption and anti-counterfeiting using thermal-induced afterglow luminescence.

Conclusions:

• Accurate modulation of oxygen vacancies via Eu3+ doping in ZnGa2O4 is achievable.
• These phosphors show significant potential for high-performance temperature sensing and secure optical data applications.
• The findings pave the way for novel applications in optoelectronics and security.