ABSTRACT
Optical excitations in condensed matter are called excitons. An exciton could be considered as an entity consisting of an electron which has been excited so much as to leave its own atom and the positive charge that it has left behind. In molecular crystals, electron and hole remain at the molecule, and these excitons are called “low radius excitons.” The electron wave functions of neighbor molecules have a weak covering. In semiconductors, hole is in valence zone while particle is in the conductive zone. The connection between elements of this pair remains stable. The excitons founded in semiconductor crystals with small energy gaps and high dielectric constants were named for Gregory Wannier and Nevill Francis Mott. The exciton interactions were studied by nonlinear optics. The analysis of non-conserving excitons in short one-dimensional chain has shown that it fundamentally differs from the corresponding infinite linear chain. Macromolecules whose number of excitons is not conserved are very important for biophysical processes.
