Catalyst-free growth of single crystalline β-Ga2O3 microbelts on patterned sapphire substrates

•The high density and large quantity β-Ga2O3 microbelts were synthesized on PSS by CVD method.•The width and length of microbelts were about 1–1.5 μm and 15 μm, respectively.•The hemispherical PSS played an important role for β-Ga2O3 microbelts formation.