Fig. 1. SEM images of samples a-d at different growth temperatures: (a) Sample A (800 ℃); (b) sample B (850 ℃); (c) sample C (900 ℃); (d) sample D (950 ℃).

Fig. 2. (a) The ultra-long gallium oxide nanoribbons of sample C under low magnification; (b) single gallium oxide nanoribbon at high magnification of sample C; (c) intertwined curved nanoribbons; (d) under high power, the agglomeration of the surface of the sample D nanoribbons deteriorates.

Fig. 3. (a) X-ray diffraction pattern of the sample C; (b) raman of the sample C.

Fig. 4. (a) TEM image of the sample C. Inset shows the SAED pattern; (b) HR-TEM image of the sample C.

Fig. 5. Room temperature PL spectra of β-Ga₂O₃ nanowires.