Capture from free-carrier tails in the depletion region of junction barriers

Abstract
Junction experiments have been proposed in which measurements of depletion capacitance as a function of decreasing reverse bias are used to determine the energy level of a deep trap. Since deep levels in the depletion layer are filled from the free‐carrier tail extending from the bulk, this process is slow to reach equilibrium. Calculation and experiment demonstrate this effect and it is emphasized that its neglect leads to serious misinterpretation.