High current photoconductive semiconductor switches
Photoconductive Semiconductor Switches (PCSS) are a completely different type of switch than those currently used in pulsed power applications. The most important attributes of PCSS are jitter-free triggering, low inductance, fast rise time, fast recovery (opening time), and high repetition rate. The most important limitation of the PCSS is the higher laser power required to activate them and the low-electric fields that they switch. These two issues are related because, for a given voltage that needs to be switched, a low field implies a large ''gap'' and, hence, a very large laser energy. This is especially troublesome since the laser energy required to reach a given switch resistance is proportional to the square of the gap spacing. In this paper we descibe major advances in PCSS. The first section describes how we are able to switch higher fields. Si can be used to switch fields of up to 82 kV/cm (a voltage of 123 kV across 1.5 cm), more than a factor of two higher than the 36 kV/cm that we reported a year ago. The development of PCSS for use in pulsed power application requires the ability to switch both high voltages and large currents. Having made signifcant progress in voltage standoff and switched fields, we are now concentrating on the current density issue. The second section describes the devlopment of two-impedance systems to test the maximum currents that the samples can switch. Presently the best we can switch corresponds to 4.0 kA (distributed over 2.1 cm) or 3.2 kA/cm (a current of 800 A distributed over a width of 0.25 cm) for GaAs in our sub-/OMEGA/ impedance test system. The third section focuses on the lock-on phenomenon first reported by our laboratory a year ago. 12 refs., 6 figs., 2 tabs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 7029638
- Report Number(s):
- SAND-88-0333C; CONF-880699-2; ON: DE88011541
- Country of Publication:
- United States
- Language:
- English
Similar Records
Toward pulsed power uses for photoconductive semiconductor switches: Closing switches
Surface flashover threshold and switched fields of photoconductive semiconductor switches
Related Subjects
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ARSENIC COMPOUNDS
ARSENIDES
CURRENT DENSITY
DESIGN
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
EQUIPMENT
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
MODIFICATIONS
PHOTOCONDUCTIVITY
PHYSICAL PROPERTIES
PNICTIDES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR SWITCHES
SWITCHES