The integration of lithium based compounds (e.g., Li:NiO/Ga2O3, LiGa5O8/Ga2O3) in Ga2O3 based pn-heterojunctions raises concerns about interface stability, i.e., Li diffusion effects on Ga2O3 properties. In this work the ex-situ diffusion of Li is investigated in three different Ga2O3 epilayers systems [(001) κ-Ga2O3 and (−201) β-Ga2O3 heteroepitaxy on (001) α-Al2O3, and (010) β-Ga2O3 homoepitaxy] at relevant temperatures for the synthesis / processing of Li-based epilayers. It is here experimentally demonstrated and quantified the Li diffusion in all the investigated Ga2O3 epilayers systems and Li bulk (DLi,bulk) and 2D defects (DLi,2D) diffusion coefficients are provided. In the case of the (010) β-Ga2O3 homoepitaxial layer (nominally free of structural defects), hybrid functional theory calculations foresee a diffusion mechanism mediated by Ga vacancies (VGa). Moreover, in the (010) β-Ga2O3 homo-layer a significant effect on its functional properties (e.g., additional Raman vibrational modes, induced conductivity in an otherwise insulating sample) upon the Li-diffusion process is experimentally highlighted and tentatively related to the passivation of acceptor defects (i.e., formation of VGa-nLi complexes).
Effect of lithium diffusion into Ga2O3 thin films
Sidoli M.;Bosi M.;Seravalli L.;Spaggiari G.;Mezzadri F.;Fornari R.;
2025
Abstract
The integration of lithium based compounds (e.g., Li:NiO/Ga2O3, LiGa5O8/Ga2O3) in Ga2O3 based pn-heterojunctions raises concerns about interface stability, i.e., Li diffusion effects on Ga2O3 properties. In this work the ex-situ diffusion of Li is investigated in three different Ga2O3 epilayers systems [(001) κ-Ga2O3 and (−201) β-Ga2O3 heteroepitaxy on (001) α-Al2O3, and (010) β-Ga2O3 homoepitaxy] at relevant temperatures for the synthesis / processing of Li-based epilayers. It is here experimentally demonstrated and quantified the Li diffusion in all the investigated Ga2O3 epilayers systems and Li bulk (DLi,bulk) and 2D defects (DLi,2D) diffusion coefficients are provided. In the case of the (010) β-Ga2O3 homoepitaxial layer (nominally free of structural defects), hybrid functional theory calculations foresee a diffusion mechanism mediated by Ga vacancies (VGa). Moreover, in the (010) β-Ga2O3 homo-layer a significant effect on its functional properties (e.g., additional Raman vibrational modes, induced conductivity in an otherwise insulating sample) upon the Li-diffusion process is experimentally highlighted and tentatively related to the passivation of acceptor defects (i.e., formation of VGa-nLi complexes).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
