Novel High Current Switch for Spacecraft Power Bus Control

The proposed semiconductor-insulator-semiconductor (SIS) is herein defined as a structure consisting of two semiconductor layers separated by an insulator. PTS proposes such a SIS structure as a latching on/off switch consisting of widebandgap (WBG)semiconductors as cathodes and anodes. The cathode will be designed as an efficient electron gun or cathode. The anode will be designed as both an efficient electron receiver as well as a hole emitter. The design will take advantage of the high thermalconductivity materials to dissipate the anode heat. The SIS insulator will be a vacuum, gas or solid. Both anode and cathode emitting/receiving surfaces will be designed as a low work function or negative electron affinity emitters. Initial devices werebuilt from float zoned Si as early commertial devices. Devices are currently being tested for Mil-S-19500 qualification in aerospsce applications.Ambipolar tunneling through charge neutral materials or vacuum will enable sub nanosecond switching times at temperatures approaching 300C (package limited). Switched current densities will approach PPT (Pulse Power Thyristor) current densities of ~5E4Amps/cm2 at unlimited di/dt.