The effects of a piezoelectric field on the spectroscopic properties of strained InAs/GaAs self-assembled quantum dot (QD) heterostructures grown on (N11) substrates with A or B termination are presented. An increasing blue shift of photoluminescence (PL) band was observed with increasing excitation density. The PL blue shift of (N11) quantum dots measured at the highest elicitation grows with 1/N and shows an asymmetric dependence on whether the substrate has A or B termination. We attributed the blue shift of the photoluminescence band to the screening of the piezoelectric held by the photo-generated carriers, leading to a reduction of the piezoelectric induced quantum confined Stark effect.