INTERIMPURITY TRANSITIONS IN HEAVILY DOPED SEMICONDUCTORS

We report on the first observation of theoretical predictions that, even in the case of a single acceptor level, the luminescence spectrum can have more than one peak depending on the temperature and pumping rate. Two peaks are observed: One peak (peak A) is related to the tail-impurity transition, and the other (peak B) to the band-impurity transition. The intensity of peak A is quenched at low and high temperatures, reaching its maximum value at about 30 K. At a high current and high temperature, peak B dominates and its energy increases with temperature.