Role of the thermophoretic force on the transport of nanoparticles in dusty silane plasmas

A comparison, based on numerical modeling, is made between the different forces experienced by nanoparticles present in a low pressure capacitively coupled parallel-plate silane (SiH4) discharge. We investigate in particular the influence of the thermophoretic force on the spatial distribution of the nanoparticle density profiles, due to a thermal gradient in gas temperature induced by heating or cooling of the electrodes. A series of simulations with a one-dimensional fluid model are performed with asymmetrical variation of the electrode temperatures. It appears that the resulting density profile of the nanoparticles experiences a significant shift towards the cooler electrode as soon as a temperature difference is applied. Thus thermophoresis is capable of influencing the force balance of suspended nanoparticles in the plasma, even at relatively small electrode temperature differences.