Technical: This project is to study the electronic properties of functional complex oxide-semiconductor interfaces. These interfaces are expected to provide a materials platform for basic science studies and new applications for a range of new functionalities that can impact fully depleted silicon-on-insulator technology, three dimensional integration of silicon, high dielectric constant applications, as well as potentially new channel materials at oxide-semiconductor interfaces, including magnetic semiconductor systems. Epitaxial oxide-semiconductor heterostructures will be grown using the atomic layer sequencing capability of an oxide molecular beam epitaxy system. The structural and electronic properties of these material systems will be characterized using atomic force microscopy, reflection high energy electron diffraction, photoemission spectroscopy, and x-ray diffraction. Electrical transport properties will be studied using resistivity, mobility, capacitance-voltage, inelastic tunneling electron spectroscopy, and Hall effect measurements. In addition, magnetotransport measurements will be carried out on Mn-doped oxide-semiconductor structures, including magnetoresistance, anomalous Hall effect, and planar Hall effect measurements, along with magneto-optical Kerr effect and superconducting quantum interference device measurements.
The project addresses basic research issues in a topical area of materials science with high technological relevance. The oxide-semiconductor interfaces are expected to provide a materials platform for new electronic functionalities. The project will provide graduate student training in a highly interdisciplinary area. In addition, it will introduce undergraduate students to the science of molecular beam epitaxy, which offers pedagogical opportunities to describe in a systematic fashion the details of epitaxial growth of ultrathin films, including the use of in situ diffraction techniques, the use of atomic absorption to measure evaporant fluxes and deposition rates, and the determination of phase equilibria from in situ measurements. The project will continue and expand existing collaborations with industrial companies, national laboratories, and international institutions.
