Joonghan Kim

Femtosecond X-ray Tracking of Oxygen Vacancy-Driven Shallow-to-Deep Trap Transition and Its Impact on Charge Carrier Dynamics in Blue TiO2

Abstract Oxygen vacancies introduced by self-reduction are central to the enhanced light absorption and photocatalytic activity of blue TiO2, yet how they reshape the ultrafast dynamics of photogenerated charge carriers has remained unresolved. Here, we directly track these dynam...

Direct Observation of Radical‐Mediated Oxide‐to‐Alloy Transformation in Solution Under Pulsed Laser Irradiation

ABSTRACT Pulsed laser irradiation (PLI) is widely used to synthesize metal‐based functional materials in solution, yet the molecular‐level mechanism by which a laser pulse reduces a metal‐oxide precursor has remained unresolved. Here we combine time‐resolved in situ x‐ray absorpt...