CAREER: Rational Design of One-Dimensional Contacts to Two-Dimensional Atomically Thin Heterostructure for High-Performance and Low Noise Field Effect Transistors and Biosensors

Field Effect Transistors (FETs) with two-dimensional atomically thin materials and one-dimensional contacts are studied in this project. These transistors will demonstrate high performance and low noise characteristics and will lay the foundation for emerging technologies including biosensor devices and circuits. Though silicon-based electronics have been the basis for innovation for several decades, their performance at atomically thin dimensions breaks down due to the bottleneck in its intrinsic crystal symmetry and associated physical and chemical properties. This project investigates the use of graphene, hexagonal boron nitride, and transition metal dichalcogenides to form atomically thin FETs. Given their unprecedented physical properties such as material and device tunability and energy efficiency at the atomic level, these devices will revolutionize the use of FETs in new applications that will transform electronics across industries such as communications, healthcare, and environmental sensing. It is expected that these devices and circuits that deploy them will play a great role in the development of internet-of-things (IoT), Industry 4.0, data analytics, artificial intelligence, and machine learning. This project will train next generation researchers, including women scientists and engineers and those from underrepresented populations, in micro-nanoscale science and engineering to gain expertise in addressing some of the complex societal problems such as creating sensors for environmental monitoring to disease diagnostics. The results obtained from this project will be integrated in educational activities.

The proposed research aims to demonstrate high performance and low noise field effect transistor devices that will uniquely be used as a platform for highly sensitive biosensors. The objectives of the proposal is to rationally design to study correlated electrical transport and noise phenomena in number of two dimensional atomically thin heterostructure field effect transistors involving graphene, hexagonal boron nitride, and transition metal dichalcogenides (such as molybdenum disulfide) by understanding (1) contact engineering with low work function metals and semimetals as source and drain electrodes, (2) edge contacted architectures with large transfer length and low contact resistance, (3) manipulating polar phonons by dielectric engineering using isotopically pure hexagonal boron nitrides and (4) development of antibody/antigen immunosensors with high sensitivity for SARS-CoV-2. Key to all these successes requires a fundamental understanding in material tunability in atomic scale, quantum confinement and relation to band structure, device architecture and integration, and correlated phenomena between electrical transport and noise physics. Based on experimental design parameters and results (such as a two probe vs. four probe measurement design), new device models beyond the traditional silicon transistor and biosensor model will be developed. Quantum confined physics will be exploited to demonstrate their structure and property tunability and their relation to the functionality (e.g., sensing characteristics).

This project is jointly funded by ECCS and the Established Program to Stimulate Competitive Research (EPSCoR).

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.