# 57. Highly tunable, polarization-engineered two-dimensional electron gas oxide heterostructures

P. Ranga, S. B. Cho, R. Mishra, S. Krishnamoorthy, Appl. Phys. Express (2020).

# Highly tunable, polarization-engineered two-dimensional electron gas in *ε*-AlGaO_{3}/*ε*-Ga_{2}O_{3} heterostructures

P. Ranga, S. B. Cho, R. Mishra, S. Krishnamoorthy*, Appl. Phys. Express* **13** 061009 (2020).

We report on the modeling of polarization-induced two-dimensional electron gas (2DEG) formation at *ε*-AlGaO_{3}/*ε*-Ga_{2}O_{3} heterointerface and the effect of spontaneous polarization (*P* _{sp}) reversal on 2DEG density in *ε*-Ga_{2}O_{3}/*ε*-AlGaO_{3}/*ε*-Ga_{2}O_{3} double heterostructures. Density-functional theory (DFT) is utilized to calculate the material properties of *ε*-Ga_{2}O_{3} and *ε*-AlGaO_{3} alloys. Using Schrödinger–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 *ε*-Ga_{2}O_{3}/*ε*-AlGaO_{3}/*ε*-Ga_{2}O_{3} heterostructures, charge contrast ratios exceeding 1600 are obtained. This computational study indicates the high potential for *ε*-Ga_{2}O_{3}-based heterostructure devices for non-volatile memories and neuromorphic applications.