Effect of external electric field on morphology, structure and optical properties of β-Ga2O3 microstructures grown by CVD method

Uniform and regularly arranged beta-Ga2O3 microstructures were grown on patterned sapphire substrates (PSS) by the external electric field assisted chemical vapor deposition method at applied voltages in the range of 0-80 V. It was found that the voltage has a significant effect on the growth rate, surface morphology and crystalline quality of beta-Ga2O3. When the external voltage increases, the beta-Ga2O3 growth rate on the PSS increases and the crystal quality improves. When the external voltage is 80 V, a beta-Ga2O3 thin film with high crystalline quality was obtained. Furthermore, the absorption spectra indicated that the absorption edge of the samples showed a blue shift with increasing external voltage. These results show that the crystal quality of the sample was improved after applying an external electric field.