Dynamic quantum-confined stark effect in self-assembled InAs quantum dots

We present a detailed investigation of the carrier dynamics in a set of InA s/GaAs (N11) quantum dots (QD) by means of time-resolved photoluminesce (PL ) techniques. A dynamical red shift of the PL bands when increasing the del ay time after the pulse excitation is observed. We attribute this intrinsic optical nonlinearity to the photoinduced screening of internal built-in el ectric field. The value of the redshift of the QD emission band decays with the carrier population demonstrating the intrinsic nature of the built-in field. Its dependence on the substrate orientation and termination agrees w ith the expected piezoelectric induced quantum confined Stark effects of th e QD optical transitions. (C) 2001 American Institute of Physics.