Excited Terminal States of Bound Exciton Complexes

Emission from the excited terminal states of bound exciton-donor complexes has been observed in several I I — V I compounds. Studying these optical transitions allows one to determine the donor ionization energies, the electron effective masses as well as the electron (/-values in these materials. A good theoretical fit to the experimental data was obtained, using the effective mass approximation. Emission from the excited terminal states o f bound exciton-acceptor complexes has not yet been observed in these materials. There is no basic reason why such transitions should not occur. Studying transitions o f this type would allow one to obtain fundamental information concerning the acceptor impurities in these materials.