| Abstract Scope |
Strain engineering has been a promising approach to control exciton dynamics and photoluminescence (PL) properties of two-dimensional (2D) semiconductors. In this talk, I will present our work on deterministic straining and confinement of excitons in atomically-thin transition metal dichalcogenides (TMDs). I will discuss predictable and reconfigurable strain engineering in atomically-thin WSe2 via three-dimensional (3D) wrinkle architectures. Strain exerted on WSe2 was periodically modulated to tensile and compressive strain at peaks and valleys of the wrinkles, respectively via 3D wrinkle architecture. By tuning wrinkling parameters and encapsulation methods, we were able to achieve PL emission shift of as much as ~200 meV, corresponding to approximately 4% strain. Furthermore, owing to the deformable nature of the wrinkle architecture, the applied strain can be tuned reconfigurably by post stretching/releasing processes, with PL shift dynamically modulated. Time-resolved PL decay measurements further revealed heterogeneous exciton recombination. |