Time-resolved force microscopy using the delay-time modulation method

Abstract

We developed a time-resolved force microscopy technique by integrating the Atomic Force Microscope tuning fork-type cantilever with the delay time modulation method of optical pump-probe light. During the irradiation of the probe light, the instantaneous formation of dipoles induces a force between the probe and the sample, enabling the stable acquisition of a time-resolved force signal with a high signal-to-noise (SN) ratio. We successfully measured the dynamics of surface recombination and diffusion of photoexcited carriers in a bulk WSe2, which are challenging due to the effect of tunneling current in the time-resolved Scanning Tunneling Microscopy.