Achieving n-type doped monoclinic (InxAl1-x)2O3 alloys.

The monoclinic (In 0.25 Al 0.75) 2 O 3 alloy has been suggested as an ideal material to create monoclinic Ga 2 O 3 heterostructures, as it provides a close lattice match to β - Ga 2 O 3 along with a 1 eV conduction-band offset. Achieving intentional n -type doping in Ga 2 O 3 heterostructures is important for device applications, but this may be difficult due to the high Al content of this alloy. Here, we use density functional theory with a hybrid functional to investigate common donor dopants, in particular, Si, Sn, C, and Ge substituting on cation sites, and H interstitials, in In 2 O 3 and InAlO 3. We identify Si as the optimal donor, as it is a shallow donor for In concentrations above 14%. Its formation energy is also low, indicating that these donors will incorporate during growth. For higher In concentrations, Sn (above 33% In) and Ge (above 35% In) are also promising donors, with Sn having comparable formation energies to Si. [ABSTRACT FROM AUTHOR]