PNNL

Abstract

We examine the mechanism of electronic bond rupture on semiconductor surfaces induced by laser-generated three-dimensional non-equilibrium valence excitation associated with strong carrier diffusion. For such excited systems, the density of sub-surface valence holes that contribute to two-hole localization on the surface is characterized by quasi Fermi level and effective temperature. The rate of two-hole localization, formulated for equilibrated two-dimensional electronic systems by Sumi [Surf. Sci, 248, 382 (1991)], is re-formulated, and a simple analytical expression is yielded for moderate excitation densities. The resulting theoretical model has been successfully applied in the analysis of recent laser-induced atomic desorption experiments on InP and Si surfaces