Highly tunable, polarization-engineered two-dimensional electron gas in ε-AlGaO3/ε-Ga2O3 heterostructures

We report on the modeling of polarization-induced two-dimensional electron gas (2DEG) formation at ${\epsilon}$-AlGaO3 / ${\epsilon}$-Ga2O3 heterointerface and the effect of spontaneous polarization (Psp) reversal on 2DEG density in ${\epsilon}$-Ga2O3 /${\epsilon}$-AlGaO3 / ${\epsilon}$-Ga2O3 double heterostructures. Density-functional theory (DFT) is utilized to calculate the material properties of ${\epsilon}$-Ga2O3 and ${\epsilon}$-AlGaO3 alloys. Using Schrodinger-Poisson solver along with DFT calculated parameters, the 2DEG density is calculated as a function of barrier type and thickness. By optimizing the layer thicknesses of ${\epsilon}$-Ga2O3/${\epsilon}$-AlGaO3/${\epsilon}$-Ga2O3 heterostructures, charge contrast ratios exceeding 1600 are obtained. This computational study indicates the high potential for ${\epsilon}$-Ga2O3-based heterostructure devices for non-volatile memories and neuromorphic applications.