Excitons in crystals. F. P. Laussy and A. Kavokin in Encycl. Cond. Mat. Phys. 3:706 (2024).   What the paper says!?

This is a completely rewritten version of the entry "Excitons in Crystals" for the 2nd edition of the Encyclopedia of Condensed Matter Physics [ISBN: 9780323908009].

It gives a mixed historical/scientific overview of what happens to the excitation of an atom when this atom is itself part of a crystal.