The probability of non-radiative multi-phonon capture of a carrier by a defect with a deep level was calculated as a function of the position of the defect in the quantum well. It was shown that the probabilities of multi-phonon emission and trapping of carriers by defects in quantum wells depended strongly upon the defect position in the well. The capture cross-section at a defect in the middle of the well was smaller than it was for a defect in the bulk. It was found that the capture cross-section increased markedly when a defect approached the boundary of the quantum well. As a result, the observed lifetimes of excess carriers were expected to be extremely sensitive to the defect distribution through the thickness of the quantum well. There was therefore considerable interest in studying quantum wells with -doped deep centers.

I.N.Yassievich, A.A.Pakhomov: Materials Science Forum, 1995, 196-201, 491-6