Luminescence energy shift and carrier lifetime change dependence on carrier density in In0.12Ga0.88N/In0.03Ga0.97N quantum wells

To clarify the carrier density dependence of carrier lifetime and luminesce nce energy, we have performed a systematic study of time-resolved photolumi nescence (PL) measurements of In0.12Ga0.88N/In0.03Ga0.97N multiple quantum wells for various carrier density. The carrier recombination rate and the P L energy, for the carrier density below 1.5 x 10(18)cm(-3), are found to de crease nonlinearly with the decrease of the carrier density, although the c arrier lifetime is constant and the PL energy shifts linearly for carrier d ensity above this value. We show that the energy shift for the small carrie r density and the change in the carrier lifetime are well explained by the free carrier screening effect which compensates the internal electric field . The linear energy shift for the high carrier density is attributed to the band-filling effect. (C) 2000 American Institute of Physics. [S0003-6951(0 0)00625-2].