Anisotropic photoluminescence of β-LiGaO2 crystal

Computational study of defect complexes in $β$-LiGaO$_2$ and their relation to the donor-acceptor-pair recombination

“…Recently, the infrared (phonon related) as well as visible ultraviolet (interband transition related) optical properties were studied by reflectivity, transmission and spectroscopic reflectivity by Tumėnas et al [24] and indicated sharp excitons near 6.0 eV. Luminescence properties were studied by Trinkler et al [25,26] and the photoluminescence excitation (PLE) spectroscopy confirmed the presence of sharp free excitons near 6.0 eV. The anisotropic splitting of these excitons, reported in [26] reflects the valence band splitting, characteristic of the orthorhombic symmetry of the crystal and is in good agreement with the recent computational study by Radha et al [17].…”

“…Luminescence properties were studied by Trinkler et al [25,26] and the photoluminescence excitation (PLE) spectroscopy confirmed the presence of sharp free excitons near 6.0 eV. The anisotropic splitting of these excitons, reported in [26] reflects the valence band splitting, characteristic of the orthorhombic symmetry of the crystal and is in good agreement with the recent computational study by Radha et al [17]. This much larger optical exciton gap than previously accepted led one of us to re-examine the convergence of the QSGW calculations and to also study the excitons by means of the Bethe-Salpeter-Equation method and not only found resuls in close agreement for the exciton gap near 6.0 eV but also found a large exciton binding energy of about 0.7 eV.…”