PYROELECTRIC EFFECT IN SEMICONDUCTOR HETEROSTRUCTURES

In heterostructures made of dielectric or semiconductor materials a reduction in symmetry can lead to a pyroelectric effect in the heterostructure, even though the effect is forbidden by symmetry in the bulk-crystal constituent materials. The pyroelectric effect resulting from an applied electric field and a built-in strain is estimated for the cases of a [100] and [111] growth-axis GaAs-AlGaAs and GaAs-InGaAs quantum well. The effect is shown to produce pyroelectric coefficients on the order of p(i) = 10(-6) C/m2 K, which is comparable to some bulk-crystal pyroelectric materials.