Two-Dimensional Material-based Quantum Tunneling Devices using a Lithography Free Method


Thu, 06 Aug 2020, 01:00 pm - 02:00 pm
Graduate Thesis Defense - Current
Ali Alzahrani


This proposed work describes fundamental research to develop various quantum tunneling devices using two dimensional (2D) materials. It is aimed to realize quantum tunneling devices of 2D materials with scalable material processing steps without the use of lithography techniques, which restricts rapid development of 2D materials-based tunneling devices. Since hexagonal boron nitride (h-BN) has a great potential to be used as the tunneling barrier layer in functional, vertically stacked heterostructures, the combination of graphene and h-BN opens up the exciting possibility of creating a new class of tunneling devices. In particular, we focus on the situations where (i) the two graphene sheets have unequal doping levels in a single tunneling junction device and (ii) the tunneling device consisting of two vertically stacked junctions (double barrier) to achieve resonant tunneling. The employment of the vertically stacked geometry enables us to overcome both (i) the lithographical limitations inherent with in-planar geometry and (ii) poor scalability at large current modulations. Most importantly, this process enables us to extend this study beyond graphene to incorporate superconducting and ferromagnetic 2D materials to achieve Josephson tunneling junctions and magnetic tunneling junctions respectively.