Transient and alternating currents in insulators or semiconductors: influence of generation and recombination of carriers

The transient current in a dielectric material or a semiconductor is calculated. Mathematical expressions taking into account the generation and recombination phenomena at a single level are given. The transient behaviour is governed by two time constants which are connected in a simple manner to fundamental parameters of the sample studied, such as density, mobility, diffusivity of the carriers, and generation and recombination coefficients. The expression for the complex dielectric constant is also derived; it shows that two Debye-type dispersion regions exist.