Exploring the Optical Signatures and Dynamics of Interlayer Excitons in 2D Heterostructures

Abstract

This dissertation presents a comprehensive study of interlayer excitons in twodimensional heterostructures. This research field was born with the fabricationof a single layer of graphene utilizing the Scotch tape method, an event that marked a rapid evolution in the field of 2D materials. The exploration of various types of materials, including semiconductors, superconductors, insulators, and others, in the 2D limit has been undertaken. These materials offer intriguing properties that can be readily manipulated by electric fields, doping, stacking, layer twisting, and strain, establishing an excellent platform for studying phenomena such as correlated states, superfluidity, and Bose-Einstein condensation. The primary focus of this dissertation is the dynamics of optically active interlayer excitons in 2D materials, with an emphasis on semiconductors heterostructures such as the ones formed from MoSe2 and WSe2. This research uncovers novel fundamental properties of these structures and evaluates their potential for further applications in industry, particularly in quantum technologies, valleytronics, and twistronics. This work delves into the capabilities and constraints of these materials, providing a roadmap towards engineering potential platforms for future research. The dissertation incorporates rigorous studies of several devices with varying twist angles and stacking arrangements, offering a comprehensive investigation of the optical properties of these systems under cryogenic temperatures. Parameters such as carrier density and magnetic fields are modulated to gain insights into the properties and behaviours of these fascinating 2D materials. In this dissertation, we provide insights into the twist angle-dependent behavior of heterostructures as a function of temperature. We also shed light on the origin of single quantum emitters of interlayer excitons in this system.