The dielectric response of a dilute suspension of semiconducting particles

The aim of this note is to draw attention to the interesting electrical properties of aqueous suspensions of semiconducting particles. The charge carriers in these particles have a very high mobility, and, as a result, large polarization currents are set up when an external field is applied. For spherical particles this has the effect of causing the particles to behave like dielectrics with an enhanced permittivity epsilon*. The value of the effective permittivity depends on the ratio of the particle radius to the internal Debye length of the semiconductor. A formula for epsilon* is obtained in the case when the equilibrium charge carrier distribution is uniform over the particle. (C) 1996 Academic Press, Inc.