Temporally Tracking Exciton Funneling Process in Strain Gradient

Manipulation of exciton transport not only enables control over the information conveyed by excitons but also facilitates the creation of novel quantum states, making it a crucial element in excitonic quantum devices. Due to the neutral nature of excitons, strain manipulation provides a more potent and efficient avenue for exciton transport than electric field control. To explore the spatial and temporal funneling process of excitons within a strain gradient, ultrafast and time-resolved readout techniques are utilized. Employing transient absorption microscopy, the movement of excitons within the strain gradient is monitored, a phenomenon described by a 1D diffusion equation that incorporates the strain gradient. The results demonstrate that strain not only dictates the direction of exciton flow but also accelerates the rate of exciton transport. These findings highlight a fundamental alteration of exciton transport properties in strained 2D materials, offering significant implications for both solid-state science and excitonic devices.