THE SUM-RULE FOR THE LUMINESCENCE OF SEMICONDUCTORS DOPED WITH TRANSITION-METAL IMPURITIES

A theory of two complementing luminescence lines observed in some A(II )B(VI) semiconductors doped with transition metal impurities is propos ed. The first line is known to be attributable to an intracentre trans ition; the second line appears as a result of a second-order process o f interference between radiative and non-radiative transitions with pa rticipation of the d shells of the impurity atoms. A detailed calculat ion of the intensity of such a process is presented. It is shown that the specific resonance can make this second-order process quite strong if the impurity-phonon coupling is strong enough. The possibility of observing pairs of complementing lines in various A(II)B(VI) and A(III )B(V) systems is discussed. Some unresolved problems associated with t he effect are also touched upon.