ABSTRACT
In nanomaterials increasingly important phenomena affecting the optical properties (absorption, reflectance, luminescence etc.) are quasiparticle excitations related to the excitons. As the result of the interaction of incoming photons and bounded electrons in the materials the optically excited electron leaves behind a hole in the valence band, which behaves as a positive charge carrier. The electron interacts with this hole through a screened Coulomb potential and may therefore form bound states. The resulting bound electron-hole pairs are known as excitons.
