1：Experimental Design and Method Selection:

The study involved using thermo-optical treatment (TOT) on anion-deficient corundum crystals to create complex centers, with comparisons made to neutron-irradiated stoichiometric samples. Optical absorption (OA) and photoluminescence (PL) spectra were measured at low temperatures to analyze vibronic structures.

2：Sample Selection and Data Sources:

Nominally pure anion-deficient single crystals of α-Al2O3-δ were used, grown under reductive conditions. Neutron-irradiated stoichiometric α-Al2O3 samples served as references.

3：List of Experimental Equipment and Materials:

Equipment included a Cary 60 spectrophotometer for OA measurements, a Janis optical helium cryostat for PL at 8 K, a DKSSh-150 xenon lamp with an MSD-1 monochromator, continuous wave semiconductor lasers (hn ex=2.75 eV and hn ex=1.88 eV), a Hamamatsu R6356 multiplier tube, an InGaAs photodiode Hamamatsu G10899-02K, and an MDR-23 monochromator. Materials included α-Al2O3-δ crystals and neutron-irradiated α-Al2O3 crystals.

4：75 eV and hn ex=88 eV), a Hamamatsu R6356 multiplier tube, an InGaAs photodiode Hamamatsu G10899-02K, and an MDR-23 monochromator. Materials included α-Al2O3-δ crystals and neutron-irradiated α-Al2O3 crystals. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: TOT was performed by irradiating heated α-Al2O3-δ crystals with UV light from a DRT-240 mercury lamp at 1120 K for 10 minutes with an energy density of 15 J/cm2. OA spectra were measured at 80 K and 295 K, and PL spectra at 8 K using specified excitation sources and detectors.

5：Data Analysis Methods:

Vibronic structures of OA and PL bands were compared between TOT-treated and neutron-irradiated samples to identify similarities in zero-phonon lines and phonon-assisted lines.