Externally generated piezoelectric effect in semiconductor micro- structures

We report a study of the effects of large, external uniaxial stress (T) along [001] and [110] on the optical properties of a strained layer (001) ${\mathrm{In}}_{0.21}$${\mathrm{Ga}}_{0.79}$As/GaAs single quantum well. For T∥[110] we have observed a red shift of several peaks and an increase in the intensities of several ‘‘symmetry-forbidden’’ transitions; effects not seen for T∥[100]. This phenomenon is due to an electric field along [001] induced by the piezoelectric coupling for T∥[110].