An Optically Gated InP Based Thyristor for High Power Pulsed Switching Applications

Abstract

An MOCVD grown InP based optothyristor has been fabricated and tested for high power pulsed switching applications. To increase the power handling capability, the thyristor structure has a 250 pm thick Fe doped semi-insulating(SI) InP sandwiched between two pn junctions of a conventional thyristor. The turn-on of the thyristor is controlled by optical illumination on the SI-InP which creates a high concentration of electron and hole pairs. More than 1,100 V device hold-off voltage has been observed and over 66 A switched current has been realized with a di/dt rating of 1.38x10`° A/s. The switched current as a function of switch voltage and of optical illumination power has also been studied. Comparison with the switching characteristics of a bulk SI-InP photoconductive switch dearly indicates the advantage of this optothyristor in terms of power handling capability.