Characterization of deep impurities in semiconductors by terahertz tunneling ionization

Tunneling ionization in high-frequency fields as well as in static fields i s suggested as a method for the characterization of deep impurities in semi conductors. It is shown that an analysis of the field and temperature depen dences of the ionization probability allows to obtain defect parameters lik e the charge of the impurity, tunneling times, the Huang-Rhys parameter, th e difference between optical and thermal binding energy and the basic struc ture of the defect adiabatic potentials. Compared to static fields, high-fr equency electric fields in the terahertz-range offer various advantages, as they can be applied contactlessly and homogeneously even to bulk samples u sing the intense radiation of a high-power pulsed far-infrared laser. (C) 2 001 Elsevier Science Ltd. All rights reserved.