Photosensitivity of structures with quantum wells under normal radiation incidence

The results of investigations of photosensitivity are presented for normal radiation incidence to structures with quantum wells grown by molecular-beam and gas-phase epitaxy methods but having nominally identical construction. It is established that the samples grown by gas-phase epitaxy have higher sensitivity. The samples grown by molecular epitaxy are more sensitive to radiation that has a component of the electric-field vector perpendicular to the layers of structures with quantum wells. On the basis of the obtained results, it is assumed that the photosensitivity selectivity relative to the radiation polarization in the samples grown by the gas-phase method is appreciably suppressed. The occurrence of a built-in electric field related to the penetration of an impurity into barriers during the growth of structures with quantum wells at the barrier-well interfaces is considered among the most probable causes of this effect.