COLLABORATIVE RESEARCH: RATIONAL DESIGN AND ENGINEERING OF ATOMICALLY THIN INTERFACES FOR ELECTRONIC DEVICES

The contact between metals and semiconductors is the foundation of modern day electronics. The high performance at relatively low energy cost in today's field effect transistors is achieved by decades long optimization of electrical contacts that has allowed the miniaturization of the device down to nanoscale dimensions. The search for new materials and devices to continue the development of advanced electronic has focused on 2-dimensional (2D) materials such as MoS2. 2D semiconductors that are naturally atomically thin can in principle provide higher performance. While the materials can provide advantages, their implementation is limited by the lack of a useful strategy to make electrical contact to the device. This grant looks to the fundamental nature of these contacts. The combined computational and experimental approach will seek new contact materials and structures to overcome this technological barrier. New contact strategies will be discovered and demonstrated leading to advances in the use of these new materials. Undergraduates will be engaged in the research activities drawing upon and developing underrepresented students into the work. The research seeks to develop a fundamental understanding of atomically thin interfaces formed between two dimensional (2D) materials with disparate properties. The lateral integration of 2D materials is a unique scientific problem that has not been systematically investigated. Novel atomic structures will be identified that are due to deformation induced by interfacial stress as well as the presence of new types of defects when two materials are 'stitched' together. The work examines the role of defects and the strain induced at the structural interface using multi-scale theoretical models, detailed structural characterization, and correlation of mechanics of the interface with electronic transport in field effect transistors. An iterative design approach will be developed that utilizes theoretical models to predict desired properties, experimentally realize hetero-interfaces of 2D materials, and characterize their atomic structure. The experimental work will provide input parameters for refinement of calculations while theoretical models will down select important combinations of 2D materials. This grant develops new theoretical and experimental methods for designing atomically thin interfaces with key 2D materials and their implementation as high performance electrical contacts for electronic systems. The materials selection knowledge for electrical contacts for 2D semiconductors will enable the next generation of high performance electronics that dissipate less heat leading to more energy efficient devices and do not require sophisticated thermal management strategies. The work incorporates undergraduates into the research activities drawing from underrepresented groups.