Luminescence of excitons’ treats in a comprehensive way a series of luminescence manifestations of bound electron–hole pairs, i.e. excitons. First, the concept of a free Wannier exciton is introduced and a shape of the pertinent absorption spectrum is described. Then multiple luminescence effects due to the free exciton radiative recombination are discussed in direct bandgap materials (exciton–polariton luminescence and LO-phonon assisted exciton annihilation) as well as in indirect bandgap materials (no-phonon luminescence, phonon replicas). Relevant selection rules are derived. Various...

Luminescence of excitons’ treats in a comprehensive way a series of luminescence manifestations of bound electron–hole pairs, i.e. excitons. First, the concept of a free Wannier exciton is introduced and a shape of the pertinent absorption spectrum is described. Then multiple luminescence effects due to the free exciton radiative recombination are discussed in direct bandgap materials (exciton–polariton luminescence and LO-phonon assisted exciton annihilation) as well as in indirect bandgap materials (no-phonon luminescence, phonon replicas). Relevant selection rules are derived. Various kinds of excitons bound to impurities (neutral and/or ionized donors and acceptors, Haynes’ rule) are dealt with. Description of the luminescence of bound multiexciton complexes follows. The application of the bound exciton concept to quantitative impurity analysis in silicon is described. Finally, the cases of excitons bound to isoelectronic impurities and of self-trapped excitons are analyzed. Whenever meaningful, a particular characteristic emission lineshape that helps to decipher experimental spectrum is pointed out.