Research Projects

The objective of the project is to develop innovative device architectures that harness the unique properties of 2D bismuth oxyselenide (Bi₂O₂Se) and its native oxide (Bi₂SeO₅) for next-generation electronic applications. Bi₂O₂Se stands out due to its exceptional properties such as ultra-high field effect mobilities, excellent thermal stabilities, strong spin-orbit coupling, and the ability to form high-k native oxide,Bi₂SeO₅. The project will focus on selective oxidation and precise patterning to create vertical and lateral heterostructures of Bi₂O₂Se/Bi₂SeO₅ and monolayer/multilayer Bi₂O₂Se using advanced nanoscale fabrication techniques. The project will leverage the unique properties of Bi₂O₂Se and Bi₂SeO₅ by fabricating novel device architectures, such as electrostatically confined quantum dot structures, with the ultimate goal of demonstrating single-electron transistors for cutting-edge quantum and high-speed electronic applications. To keep up with Moore’s law, there has been a push to move beyond silicon and von Neumann architecture with emerging technologies such as quantum computing. While 2D materials like graphene and TMDCs show promise, they are often limited by scalability and quality issues associated with vapor-deposited films. Bi₂O₂Se, a new entrant to the 2D materials family, offers a promising alternative. It holds potential for classical FETs and advanced solid-state quantum devices, bridging the gap between current semiconductor technology and future quantum computing architectures. The first part of the project will involve the chemical vapor deposition of high-quality single crystals of Bi₂O₂Se. CVD growth will be carried out in a split tube furnace with a 2-inch quartz tube containing the target substrate (SiO₂, Mica, SrTiO₃, LaAlO₃) downstream of the high-purity precursor. Once high-quality films of Bi₂O₂Se are grown via CVD, the next step will focus on the high-k native oxide of Bi₂O₂Se. This will involve the oxidation of the top layer of Bi₂O₂Se films to form Bi₂SeO₅ as the native oxide layer. The next step will involve the fabrication of heterostructures for charge confinement applications. The first scheme will focus on the formation of vertical Bi₂O₂Se/Bi₂SeO₅ heterostructures. This will involve the oxidation of the CVD-grown films followed by selective etching of the oxide layer to form FETs. The second approach will target the fabrication of Bi₂O₂Se multilayer/monolayer lateral heterostructures by etching the selectively oxidized portions of the films. These heterostructures will leverage the thickness-dependent band gap of Bi₂O₂Se for effective charge confinement.