Chalcogenide Spin Injection from Iron- and Nickel-Based Edge Modulation Doping

Transition metal dichalcogenides (TMDs) possess physical properties that make them potentially useful as both thermoelectric and topological insulator materials. Rapid, high-yield synthesis of TMDs like bismuth telluride, antimony telluride and bismuth selenide is possible through solution-liquid-solid (SLS) colloidal chemistry techniques. Subsequent edge modulation doping with noble metals (e.g. silver and copper) is known to enhance TMD thermoelectric parameters such as conductivity and the Seebeck coefficient. Iron and nickel may also play roles as useful dopants thanks to their magnetic properties and potential for spin injection at the chalcogenide-dopant interface.<br/><br/>In this study, bismuth telluride and antimony telluride were synthesized and then doped with different iron and nickel concentrations using SLS chemistry. Preliminary studies of magnetic and thermoelectric performance to assess the extent of doping and its effects on the chalcogenide’s physical properties are ongoing. Analysis of edge doping is undertaken through a variety of techniques including electron microscopy, X-ray Photoelectron Spectroscopy (XPS), Hall effect measurements, and thermoelectric measurements. If successful, the SLS chemistry approach represents a relatively low cost and straightforward strategy for making iron- and nickel-doped TMD materials that may achieve spin injection. Possible applications of spin-injected TMDs range from quantum computation to quantum sensors for gravitational wave detection to biomedicine.