Relationship between critical charge density, holding current, and maximum current density in optically triggered silicon carbide thyristors

Relationship between critical charge density, holding current, and maximum current density has been studied by using an adequate numerical model for the axisymmetric configuration characteristic of the optical triggering of power silicon carbide thyristors. It is shown that the holding current I-h depends only weakly on the critical charge density of a thyristor, p(c). At the same time, the maximum current density in the state corresponding to holding current grows very steeply with increasing p(c). It is shown that the maximum current density can substantially increase with decreasing current in the axisymmetric configuration if the switched-on state occupies only a part of the total area of a thyristor.