The objective of this program is to exploit unique advantages of topological insulator based structures for optoelectronic applications. Specifically, the strong magnetoelectric interaction at the topological insulator-magnetic material interface and subsequent band engineering is the key focus as they can facilitate tailored response to an optical signal, offering an ideal environment for previously unattainable performances such as extreme sensitivity detection. The combined theoretical and experimental effort aims to achieve synthesis, fabrication, and analysis of novel topological insulator materials and layered heterostructures as well as demonstration of superior device functionalities. Intellectual Merit: The intellectual merit is that the investigation presents a basis for realizable topological insulator based devices beyond the current state-of-the art. Through the paradigm of domain matching epitaxy, the effort pursues synthesis of epitaxial topological insulator/ferromagnetic insulator hybrid structures with atomistic uniformity at the interface on a silicon compatible platform. The target materials include both Bi2Se3 and emerging cubic candidates such as inverse perovskite Sr3SnO and half-Heusler LuPtSb. The investigation also develops fundamental theoretical understanding of topological insulator properties and photo-response characteristics of various terahertz detector designs. Broader Impacts: The broader impacts are the education/training of graduate and undergraduate students in addition to advanced device development with technological importance. Of particular significance is participation and recruiting of minority students by fostering strong ties to local historically black colleges and universities. The outreach is also pursued through ASM Materials Camp, a successful annual summer event for high school students, as well as the online distance education network. This project is jointly funded by the Electronics, Photonics, and Magnetic Devices Program (EPMD) in the Division of Electrical, Communications and Cyber Systems (ECCS) and by the Electronic and Photonic Materials Program (EPM) in the Division of Materials Research (DMR).
