Speaker
Description
Abstract
Conventional photon-pump/photon-probe time-resolved techniques face inherent limitations in resolving the intricate surface and interface carrier dynamics due to constraints in spatial resolution and penetration depth. To address these challenges, we utilize scanning ultrafast electron microscopy (SUEM), a state-of-the-art technique that integrates femtosecond temporal resolution with nanoscale spatial precision, enabling direct visualization of carrier transport and recombination at surfaces and interfaces in optoelectronic materials. In SUEM, an ultrashort laser pulse initiates excitation, while a time-delayed electron pulse probes transient modifications in electron density and spatial charge distribution with unparalleled surface sensitivity. This capability is particularly crucial for investigating surface-specific carrier dynamics, which often diverge from bulk behavior in thin films, nanostructures, and two-dimensional materials. By leveraging SUEM’s unique spatiotemporal resolution, this study advances our fundamental understanding of surface and interface charge transport mechanisms, shedding light on fundamental processes that govern the performance of electronic and photonic devices.
