Thermally stimulated currents due to multiple-trapping carrier transport. I. Gaussian transport

Abstract

Non-isothermal carrier transport in an insulator with trapping states is studied for the case of approximate thermal equilibrium between free and trapped carriers. The temperature dependences of the trap parameters and of the microscopic carrier mobility are taken into account. It is shown that the carrier packet in the sample has a Gaussian shape, independently of the form of the energetic trap distribution. On this basis, a simple formula describing thermally stimulated currents (TSC) is obtained. Its accuracy is estimated by comparison with the results of Monte Carlo calculations for model trap distributions. Methods of determining the trap parameters from the measured TSC curves are considered.