Surface carrier recombination of a silicon tip under high electric field

Using laser assisted atom probe tomography, we investigate the surface recombination processes of a subwavelength Si tip illuminated by an ultrashort laser pulse under high electric field. In practice, by changing the laser wavelength, we demonstrate the presence of a very long electron-phonon relaxation time at the surface. It is experimentally shown that this behavior is common to indirect band gap semiconductors. Furthermore, a simple model is developed in this paper to explain laser wavelength dependence of our experimental results and estimate the surface recombination time.