Two-electron transitions involving a biexciton
Belyi N. M. ,Gorban' I. S. , Gubanov V. A. , Dmitruk I. N.
The luminescence spectrum of a highly excited β-ΖηΡ2 crystal revealed the presence of an inverse hydrogen-like series of bands which are interpreted as radiative transitions from the state of an exciton molecule to the ground state and the excited state of an exciton.