Semiconductor nanoparticle in an electric field

The distributions of electrons and positive charges within a spherical semiconductor nanoparticle with surface electron traps in a uniform applied electric field are studied. The minimization of the total free energy gives the resulting effective electric field, which depends on the densities of donors and surface traps, as well as on the distance from the center of the nanoparticle. It is shown that the near-surface field at a relatively low donor density in the region of its entrance to the nanoparticle significantly differs from that in the region of its departure from the nanoparticle. The induced dipole moment of the nanoparticle is calculated and different contributions to it are determined. The ranges of applicability of the results are indicated.