Piezoelectric effects in In0.5Ga0.5As self-assembled quantum dots grown on (311)B GaAs substrates

Photocurrent spectroscopy is used to investigate the quantum-confined Stark shift of ${\mathrm{In}}_{\mathrm{0.5}}{\mathrm{Ga}}_{\mathrm{0.5}}\mathrm{As/GaAs}$ self-assembled quantum dots grown on (100) and (311)B planes. By comparing the Stark shift for dots grown on (100) and $\text{(311)}\mathrm{B}$ planes, we find that in the (311)B dots, the electron and hole wave functions are displaced by a strain-induced piezoelectric field directed from the apex to the base of the dots.