An emerging n-type dopable ternary wide bandgap oxide group: In₂{Ge,Si}₂O₇

New wide band gap (WBG) semiconductors are desirable for optoelectronics and power electronics due to larger electronic band gap and higher Baliga figure of merit (BFOM). BFOM is inversely related to on-state resistance of a conducting transistor under forward bias and is a metric critical for high-power applications. Our previous computational search[1] utilized density functional theory based method and validated semi-empirical models to calculate BFOM and thermal conductivity and screened for promising metal oxides. A few promising groups of ternary compounds are identified using these two metrics that are based on intrinsic material properties. Among them, the group of In₂{Ge,Si}₂O₇ is particularly promising since these ternary compounds are predicted to be likely n-type dopable based on the branch-point energies calculated using HSE06 hybrid functional. To further examine their potentials as semiconductor devices, the next step is to understand their defect chemistries, particularly their dopability and potential dopants. Using the supercell approach that is based on first-principle electronic-structure methods to calculate the defect formation energies, we found that the group In₂{Ge,Si}₂O₇ oxides have the band gap between 2.8 and 5.4 eV and are generally n-type dopable. We also found that Zr impurity is a promising n-type dopant for them. These, together with high BFOM, make In₂{Ge,Si}₂O₇ promising candidates for high-power applications.