The retarded diffusion of polar molecules in an assembly of conducting nanoparticles and its influence on the sensitivity of semiconductor sensors

Abstract

The influence that the electric dipole moment of the molecules has on the characteristics of their diffusion in the environment of a large amount of close-packed conductive particles has been investigated. We have neglected the molecule adhesion to the particle surface and examined the multiple interaction between the dipole moment and electron density fluctuations induced in the particles. This attractive interaction substantially decelerates the diffusion of the cloud of polar molecules more than that of non-polar molecules. The correction value to classical diffusion is determined primarily by the concentration of conduction electrons within the particles. This correction value is minor for metallic particles but becomes quite substantial for semiconductor ones. The strong dependence that the correction values to classical diffusion have on the dipole moment of the molecules calls one’s attention, because these correction values are proportional to the forth power of the dipole moment.