Optical properties of SrF₂ and SrF₂:Ce³⁺ crystals codoped with In³

Area of Science:

• Solid State Physics
• Materials Science
• Quantum Chemistry

Background:

• Strontium fluoride (SrF2) is a widely used optical material.
• Understanding impurity effects is crucial for optimizing material performance.
• Cerium (Ce3+) doping enhances luminescence in SrF2.

Purpose of the Study:

• To investigate the impact of Indium (In3+) ion impurities on the optical properties of SrF2 and SrF2:Ce3+ crystals.
• To elucidate the role of In3+ in modifying the electronic band structure and excitation transfer processes.

Main Methods:

• Optical spectroscopy was employed to analyze crystal properties.
• Ab initio quantum chemical calculations, specifically Density Functional Theory (DFT), were used.
• DFT calculations estimated the effect of In3+ on the optical band gap of SrF2.

Main Results:

• Indium doping was found to alter the optical band gap of SrF2 crystals.
• In SrF2:Ce3+ co-doped with In3+, indium ions significantly reduce electron trapping efficiency.
• This reduction in electron trapping enhances excitation transfer to the activator (Ce3+).

Conclusions:

• Indium impurities effectively modify the optical properties of SrF2 crystals.
• The observed improvements in excitation transfer are attributed to indium-induced changes in the band gap.
• Both theoretical calculations and experimental data support these findings.