MAGNITUDE AND POLARITY OF STRAIN-INDUCED FIELDS IN PSEUDOMORPHIC IN0.2GA0.8AS QUANTUM-WELL STRUCTURES ON (112) GAAS SUBSTRATES

When pseudomorphic (in,Ga)As/(Al,Ga)As heterostructures are grown on c ertain surfaces of the general crystallographic planes of GaAs denoted by (11l), the strain in the structures induces an electric field beca use of the piezoelectric nature of the III-V semiconductors. We report the experimental determination of the direction and magnitude of the strain-induced electric field by photoluminescence spectroscopy on one of these substrate surfaces: the one for which l = 2. We confirm that for the mio surfaces of the (112) GaAs substrate. the induced field i s directed out of the substrate for the A surface and toward the subst rate for the B surface.