Strain-Generated Internal Fields in Pseudomorphic (In, Ga)As/GaAs Quantum Well Structures on {11l} GaAs Substrates

A study of the piezoelectric effect in pseudomorphic (In, Ga)As/GaAs multiple quantum well structures grown on GaAs substrates oriented in the general [11 l ] direction is reported. Theoretical calculations of the transverse polarization fields and longitudinal electric fields are presented. The calculated electric fields for the [111]- and [112]-oriented structures are compared to experimental estimates reported by other workers. Additional results to support the validity of the method are provided for structures on (110) surfaces intentionally misoriented by 6° toward the (111)B surface. The pseudomorphic (In, Ga)As/GaAs multiple quantum well structures grown on the vicinal (110) GaAs substrates were characterized by photoluminescence. It is shown that the luminescent peak intensity from these structures exhibits a spectral blue-shift with increasing excitation density. This shift is interpreted to be a manifestation of the screening of the internal, strain-induced field by photogenerated carriers.