Temperature-resolved photoluminescence, Raman and electrical properties of Li doped Ga2O3 nanostructure

In this study, Li-doped Ga2O3 nanostructures (Ga2O3: Li) were synthesized through thermal evaporation. The morphology of the Ga2O3: Li was found to be mainly composed of nanorods and nanosheets. Raman spectroscopy revealed that the Raman spectra after doping of sample had four additional peaks at 273 cm(-1), 428 cm(-1), 517 cm-(1)and 583 cm(-1), respectively. While the signal of Li ions was detected in the XPS spectra of sample. In Temperature-Resolved Photoluminescence, Ga2O3: Li showed an additional wider Red-IR emission peak centered at 696 nm, in contrast to undoped Ga2O3. Further, with decreasing temperature, the Red-IR emission peak split into several peaks. Among them, the peak at 722 nm showed the largest variations with the temperature. Further analysis of the peaks reveals that it is mainly caused by the doping of Li ions. Besides, it was found that the resistance increased significantly under illumination. Especially when the illumination light is red emission, the resistance value changes most obviously, and has a correspondence with the photoluminescence spectrum. The Red-IR characteristic of Ga2O3: Li makes it a promising candidate for application in the optoelectronic devices.