Waves of switching in thyristor-like structures

Differential equations which describe a propagation of switching waves in thyristor-like structures are derived. These waves propagate if a gate current, J_g, differs from a certain value, J_g0(J), corresponding to neutral (translationally invariant) equilibrium state for a given current density j in the ON-region. The derivation is based on the initial equation of theory of semiconductor devices. Our consideration is valid only for bases where widths are much less than the width of a transition layer between the ON- and the OFF-regions. For the first time, an explicit analytical formula for the velocity of the switching wave, ν, is obtained: ν is shown to be directly proportional to δJ_g=J_g-J_g0(j) and inversely proportional to j for \δJ\≪J_g0. The dependence of the velocity ν on parameters of the structure is obtained for low injection levels in both bases. The derived expression for the velocity has been applied for calculation of transient and modulation processes in the finite gate controlled thyristor-like structures.