Investigation of p-type doping in β- and κ-Ga2O3

[摘要] We have systematically investigated the effects of all possible combinations of vacancies and silicon substitutions on the electronic structure of the beta and kappa phases of Ga2O3 using plane-wave density functional theory (DFT) methods. It was found that VGa defects are associated with a sufficient shift of the Fermi level to lower energy to induce p-type behavior, with formation energies in the range of 9.0 +/- 0.2 eV. Calculations with single atom substitutions in the kappa phase, including nitrogen, phosphorous, and silicon, did not show p-type character, although NO substitutions may lead to shallow acceptor states. In the pursuit of elucidating how MOCVD growth of Ga2O3 can result in p-type behavior, as indicated by experimental results in the literature, we examined the role of combining hydrogen and silicon substitutions. The results showed that p-type behavior is observable when gallium atoms are substituted for hydrogen within the coordination sphere of SiO substitutions. This shows that silicon can act as an amphoteric dopant for p-type Ga2O3 semiconducting materials when hydrogen is included with formation energies < 6.0 eV. (c) 2021 Elsevier B.V. All rights reserved.

[发布日期] 2021-10-05

[关键词] DFT;Defect engineering;p-Type;Semiconductor