Fig. 1. XRD pattern of the LiGa₅O₈ thin film grown on c-Al₂O₃ substrate

Fig. 2. SEM and AFM images of the LiGa₅O₈ thin film

Fig. 3. Ultraviolet and infrared spectra of the LiGa₅O₈ thin film. （a） Ultraviolet transmittance spectrum； （b） ultraviolet Tauc plot； （c） infrared transmittance spectrum

Fig. 4. XPS of the LiGa₅O₈ thin film

Fig. 5. Photodetector performance of the LiGa₅O₈ thin film （n（Li）∶n（Ga） = 0.21）. （a） Structure of the photodetector device； （b） I-V curves of dark and photocurrent under 254 nm illumination； （c） I-t curve of photoresponse time at a 10 V bias

Fig. 6. Calculated band structures of intrinsic Li and Ga substitution defects in LiGa₅O₈. （a） Band structure of a perfect LiGa₅O₈ lattice， solid line represents PBE calculation， dotted line represents GW calculation； （b） band structure with Ga_Li defects， n（Li）∶n（Ga）=0.185； （c） band structure with Li_Ga（8） defects， where Li substitutes 8-coordinated Ga， n（Li）∶n（Ga）=0.215；（d） band structure with Li_Ga（4） defects， where Li substitutes 4-coordinated Ga， n（Li）∶n（Ga）=0.215

Fig. 7. Formation energies of Ga_Li and Li_Ga defects in LiGa₅O₈ （solid line represents the formation energy of Ga_Li defects， dotted line represents the formation energy of Li_Ga defects）