Piezoelectric fields in strained (In,Ga)As/GaAs multiple-quantum-well structures grown on vicinal (110) GaAs

A study of piezoelectric-induced effects in strained (In,Ga)As/GaAs multiple quantum well structures grown on [110]-oriented GaAs substrates tilted by 6° toward the (111)B surface is presented. The elastic strain in the (In,Ga)As layers generates a large longitudinal electric field and a transverse polarization. A blue-shift in the photoluminescent emission peak with increasing excitation intensity is observed. This shift Is believed to be a manifestation of the internal strain-induced electric field. As the density of photogenerated electron-hole pairs is increased-corresponding to increasing excitation intensity-the magnitude of the electric field is reduced and the emission peak is blue-shifted