Electronic properties and device design of ferroelectric Al₂O₃/ GaN heterostructure

Two-dimensional ferroelectric material Al2O3 has mutually coupled in-plane and out-of-plane ferroelectric polarization which realize reversal polarization under the electric field. In this paper, we utilize the generalized lattice matching (GLM) method to construct two Al2O3/GaN heterostructures and investigate their electronic properties using density functional theory. The results show that the heterostructure displays semiconductor properties with band gap (E-g) of 1.90 eV when the electric dipole orientation is from GaN to Al2O3, while the heterostructure shows metallic character when the electric dipole of Al2O3 is inverted. The manipulation of vertical strains and electric fields have been found to be a highly effective means of modifying the electronic properties of Al2O3/GaN heterostructures, leading to a transition from indirect to direct E-g, as well as from semiconductor to metallic character. In addition, we design silicene-Al2O3/GaN-silicene devices with high/low resistance switching behavior based on reversed polarization of Al2O3, which provides new ideas for designing electronic switching devices.