Low-dimensional excitons are normally modeled as electron-hole pairs confined to a restricted volume. In certain cases, however, confinement to a restricted surface is a more appropriate model. These cases include one-dimensional carbon nanotubes but also various zero-dimensional structures such as small oxidized Si nanoparticles and spherical core/well/shell quantum dots. Wannier excitons confined to spherical surface quantum wells of finite and zero thicknesses are analyzed using numerical, analytical, and variational methods. The results are applied to known zero-dimensional structures supporting surface-confined excitons.

• Received 21 October 2009

DOI:https://doi.org/10.1103/PhysRevB.81.233406