Hydrogen Adsorption in Porous Silicon: Simulation and Control Method

Well-known that porous silicon is currently under consideration as new promising material for solid state hydrogen reservoirs. In present work a hydrogen adsorption processes in porous silicon are simulated. A model of hydrogen passivation of the surface of silicon pores are developed using the methods of molecular dynamics. Hydrogen-like spherical Lennard-Jones particles are used as the adsorbate. Such choice is explained by the physical nature of the adsorption processes of hydrogen on initial chemically adsorbed H-monolayer, covered the pore walls. A distribution of potential energy for interaction of the drifting species with the pore walls is calculated. Current-voltage and impedance characteristics of free standing porous silicon layers were selected as control method to study hydrogen accumulation process. The charge transfer processes were analyzed based on dependence of the impedance of porous silicon samples on voltage in the atmosphere with H2 and during relaxation in air.