On the mechanism of desorption of ions in the process of laser desorption/ionization from silicon surfaces
T11N2
A.A. Grechnikov, A.S. Borodkov, S.N. Zhabin, S.S. Alimpiev
The investigations of the mechanism of desorption of ions in the process of laser desorption/ionization from silicon surfaces are carried out with the use of pyridine and N,N-dimethyl-1-phenylethylamine as examples. On the basis of experimental and theoretical results, the dependencies of an ion signal on the surface temperature are obtained for two different wavelengths of the laser irradiation: 355 nm and 532 nm. Theoretical part of the work includes numerical calculations of the surface temperature of amorphous silicon with the aid of software package SLIM and quantum chemical calculations of binding energy between ions and silicon surface with the use of Hartree–Fock method and software package Firefly. It is demonstrated that desorption of ions occurs via the thermal mechanism at temperatures much lower than the melting point of amorphous silicon.
