PURPOSE: To enable ignition by visible light, and improve ignition sensitivity, in an optical thyristor constituted of silicon carbide.
CONSTITUTION: An optical thyristor consists of the following; four semiconductor layers composed of silicon carbide, i.e., an N-type emitter layer 21, a P-type base layer 22, an N-type base layer 23 and a P-type emitter layer 24, a cathode electrode 41 and an anode electrode 42 which are brought into low resistance contact with the main surface of the semiconductor layer, and a light guide 31 for applying an optical trigger signal. In the optical thyristor, a part or the whole part of at least one semiconductor layer is constituted as the crystal structure 11 whose band gap is narrower than that of the other part or the structure having microcrystal composed of silicon. Since the band gap energy of silicon carbide is larger than the energy of visible light, carrier is effectively generated therein, and turns the optical thyristor into the conduction state.
SAITO KATSUAKI
NAGASU MASAHIRO
