Strain-Exciton Coupling in Two-Dimensional Semiconductors

In this talk, I will present our work on deterministic manipulation and confinement of excitons in two-dimensional (2D) semiconductors. I will discuss predictable and reconfigurable strain modulation in 2D transition metal dichalcogenides (TMDs) via wrinkle architectures. Strain exerted on wrinkled 2D TMDs was periodically modulated to tensile and compressive strain at peaks and valleys of the wrinkles, respectively. Furthermore, owing to the deformable nature of the wrinkle architecture, the applied strain can be tuned reconfigurably with the optical gap of TMDs dynamically modulated. We also observed exciton transport across apex and valley of strained TMDs as well as exciton localization at the apex due to strain gradient induced energy modulation of wrinkled TMDs. Finally, I will discuss an extension of our strain modulation approach to interlayer excitons in TMD vertical heterostructures where strain is used to tune both optical gap as well as interlayer coupling between the heterobilayers. I will share our perspectives on strain-exciton engineering toward quantum and energy devices.