Band-Edge Engineering To Eliminate Radiation-Induced Defect States in Perovskite Scintillators

Area of Science:

• Materials Science
• Condensed Matter Physics
• Radiation Detectors

Background:

• Scintillation materials degrade under radiation due to induced defects.
• Novel strategies are needed to design radiation-resilient scintillators.
• Rare-earth-doped perovskites are promising scintillators but susceptible to radiation damage.

Purpose of the Study:

• Explore band-edge engineering to mitigate radiation-induced defects in rare-earth-doped perovskite scintillators.
• Investigate Ce³⁺-doped LuAlO₃ as a model system.
• Provide theoretical evidence for enhancing scintillator resilience.

Main Methods:

• Utilized density functional theory (DFT) with DFT+U and hybrid Heyd-Scuseria-Ernzerhof (HSE) calculations.
• Performed spin-polarized hybrid HSE calculations to determine electronic structure.
• Analyzed defect states and their positions relative to electronic bands.

Main Results:

• Determined the Ce³⁺ 4f ground state is 2.81 eV above the valence band maximum in LuAlO₃.
• Identified oxygen vacancies as the primary deep-level defects; other defects are shallow or outside the band gap.
• Found Ga doping in LuGaO₃ reduces the band gap by >2 eV, with the conduction band edge enveloping defect states.

Conclusions:

• Band-edge engineering effectively eliminates the impact of radiation-induced defects on scintillation performance.
• Ga doping in LuGaO₃ offers a promising strategy for creating radiation-hard scintillators.
• Theoretical insights guide the design of next-generation perovskite scintillators for extreme environments.