Molecular Beam Epitaxy and Characterization of p-Type ScGaN Nanowires for Nanoscale Ferroelectrics

Abstract

We report the epitaxial growth and characterization of p-type ScxGa1–xN nanowires on a Si substrate by plasma-assisted molecular beam epitaxy. It is observed that the incorporation of Sc can significantly enhance the axial growth rates of GaN nanowires. With controlled Mg-dopant incorporation, free hole concentrations in the range of 1017 to 1018 cm–3 in ScGaN nanowires are measured utilizing distribution of relaxation times (DRT)-assisted electrochemical impedance spectroscopy (EIS). The achievement of p-type ScGaN is further confirmed by angle-resolved X-ray photoelectron spectroscopy and photoelectrochemical measurements including open-circuit potential and photocurrent testing. These results establish p-type ScGaN nanowires as a promising nanoscale ferroelectric semiconductor platform for future memory, logic, and related device applications.