A NOVEL HIGH-POWER OPTOTHYRISTOR BASED ON ALGAAS GAAS FOR PULSED POWER-SWITCHING APPLICATIONS/

Double-side molecular beam epitaxial growth on a thick LEC-grown semi- insulating (SI) GaAs wafer has been used to demonstrate a novel high p ower optothyristor for pulsed power-switching applications. The optoth yristor has a P+N-SI-PN+ thyristor-like structure with the capital P a nd N stand for the wider bandgap optical window material, AlGaAs, and the SI stands for a 650 mum SI-GaAs substrate. With the ''insertion'' of the SI-GaAs bulk material into the conventional P+NPN+ thyristor st ructure and the use of wider bandgap AlGaAs, the device has achieved a record high performance compared to the existing GaAs or AlGaAs/GaAs based epitaxial thyristors. The performance of the optothyristors unde r forward bias has been characterized, including 1) the low field dyna mic current-voltage characteristics to show post-triggering carrier in jections, 2) the switched-current waveforms with varying device blocki ng voltage and from which the turn-on speed di/dt, and 3) the dependen ce of the switched-current amplitude on the laser triggering position.