Dynamic Evolution of Layered Chalcogenide Heterointerfaces
Abstract
Abstract:Layered metal chalcogenide semiconductors, such as WS2, MoSe2, and Bi2Te3, have the potential to improve the performance of a variety of electronic devices, including transistors, photodetectors, and sensors. In virtually all devices, these chalcogenide materials must be interfaced with various metals for charge injection and/or rectifying junction formation. It is critical to understand and control the structural, chemical, and electronic properties of suchinterfaces to optimize device performance. The highly anisotropic crystal structures of layered chalcogenides, as well as the varying chemistries and band structures of these materials, likely result in different interactions at heterointerfaces when compared to conventional semiconductorssuch as Si and Ge. However, the relationship between structure, chemistry, and electronic properties at layered chalcogenide/metal interfaces, and how these features dynamically evolve under realistic processing and operating conditions, has not been established. The objective of this proposed research is to investigate and understand the atomic-scale evolution of structural,chemical, and electronic properties at these critical interfaces during formation, processing, and device operation using multiple in situ experimental techniques. In situ transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD) will be used to reveal correlated structural and chemical evolution of chalcogenide/metal interfaces uponinitial contact, at elevated processing temperatures, and under applied bias. These in situ techniques are necessary since conventional experimental methods are insufficient for probing dynamics at buried interfaces, and they are often influenced by atmospheric exposure and other artifacts. Measurements of contact resistance and electronic properties as a function of temperaturewill be used to link interface structure/chemistry with electronic characteristics. The results of this proposed research will provide new fundamental knowledge of interfacial transformations and behavior of technologically-important layered chalcogenide semiconductors, which will establish the scientific foundation for development of advanced electronic devices. This will benefit a variety of naval applications, including low-power computing and ship-borne sensors for detection of gaseous or aqueous species.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 24, 2019
- Source ID
- N000141912195
Entities
People
- Matthew T McDowell
Organizations
- Georgia Tech Research Corporation
- Office of Naval Research
- United States Navy