REVERSE-BIASED PERFORMANCE OF A MOLECULAR-BEAM-EPITAXIAL-GROWN ALGAASGAAS HIGH-POWER OPTOTHYRISTOR FOR PULSED POWER-SWITCHING APPLICATIONS/

The reverse-biased performance of a molecular-beam-epitaxy-grown high- power optothyristor has been systematically characterized for pulsed p ower-switching applications. The device has a P+N-SI-PN+ thyristor-lik e structure with the bipolar junctions formed by AlGaAs. The semi-insu lating (SI) GaAs used is liquid-encapsulated-Czochralski grown, undope d, and 650 mum in thickness. It is found that the reverse-biased optot hyristor can be triggered by a light-emitting diode operated at 10(-5) W, and miniature semiconductor lasers can trigger the switch with 132 A current using only a 1-mm-diam optical aperture. The reverse switch ing di/dt and the maximum peak current are reported as a function of b locking voltage. The effects of bipolar junctions on both sides of the SI-GaAs are also reported by comparing the bulk photoconductive curre nt with the optothyristor switched current. It is shown that a laser b eam of 0.05 muJ can be used to trigger on and switch about the same cu rrent as a 0.3 muJ laser beam, suggesting the possibility of integrati ng miniature semiconductor lasers and the optothyristors on the same c hip to form a portable, compact, high-power solid-state pulser.