About the Low‐Temperature Dependence of Activation for Capture Cross‐Sections of Charge Carriers in Semiconductors with Persistent Photoconductivity

Abstract

AbstractA calculation is made for the capture cross‐section of charge carriers on the local centres in semiconductors taking into account the anharmonicity of highly excited states of the ground electron—vibrational term. Near the cross‐over point of the terms the anharmonic potential is approximated by a linear term that gives the decay of the excited electron—vibrational state into the continuum of states. A quantum‐statistical calculation of the multiphonon radiationless capture probability is performed with the help of the coherent states method. It is shown that activation temperature dependence for the capture cross‐section can be obtained for the low‐temperature region: k0T < hω (ω the optical phonon frequency). The developed theory is compared qualitatively with experimental data.