Effect of a dielectric thin film on the photodetachment of H- near a metal surface

The photodetachment of H- near a metal surface covered with a dielectric thin film has been studied using the closed orbit theory. The results show that the thickness and the dielectric constant of the dielectric thin film have great effect on the photodetachment of negative ion. For a given dielectric thin film, with the increase in the thickness of the film, the amplitude of oscillation of the cross section becomes strengthened and the oscillation frequency becomes decreased. If we fix the thickness of the film and vary the dielectric constant, we find the oscillating amplitude of the cross section is also changed. With the increase in the dielectric constant, the oscillating amplitude in the cross section becomes increased first and then gets decreased. This study provides a new understanding and will guide the future experiment study on the photodetachment process of negative ion in the presence of a coarse metal surface. (c) 2011 American Institute of Physics. [doi:10.1063/1.3489916]