Modulating the blue and green luminescence in the β-Ga2O3 films

In this work, the beta-Ga2O3 films were fabricated by radio frequency magnetron sputtering on the c-plane sapphire substrates with the (2 over bar 01) preferred orientation. The blue and green luminescence of beta-Ga2O3 films have been systemically studied. By changing the concentration of intrinsic vacancies in beta-Ga2O3 films through increasing oxygen flow rate during sputtering, the intensity of blue and green luminescence were modulated. The maximum value of the intensity ratio for green luminescence to blue luminescence reached to 433.37% when the oxygen flow rate arrived at 6 sccm. Combining experiments with density functional theory calculations, this work had proved the green luminescence in beta-Ga2O3 mainly originated from the isolated gallium vacancies. While the isolated oxygen vacancies could not play the important roles in the blue emission independently. The blue luminescence most likely resulted from complex defects such as (VO + VcaI) or the optical transitions between VO and (VO, VGa). Thus, changing the concentration of intrinsic vacancies is highly effective for beta-Ga2O3 to modulate the intensity of green luminescence and blue luminescence. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, beta-Ga2O3 films were fabricated on c-plane sapphire substrates with preferred orientation. The intensity of blue and green luminescence in beta-Ga2O3 films was modulated by changing the concentration of intrinsic vacancies through adjusting oxygen flow rate. The green luminescence mainly originated from isolated gallium vacancies, while the blue luminescence likely resulted from complex defects.