Development of a diamond treated photoconductive semiconductor switch for use in Blumlein pulsers

Conventional attempts to utilize photoconductive switches have focused upon nonlinear commutation of pulsers with GaAs photoconductive semiconductor switches (PCSS). However, a persistent problem in switch lifetime has limited the wide use of the switch in high power applications. Filamentation of the conductivity associated with high gain GaAs switches produces such high current density that the switches are damaged near the metal-semiconductor interface and the lifetime is severely limited. The authors' current efforts have been directed to study and implement the broadening of the current channels in the avalanche photoconductive switch in order to improve lifetime and increase switching peak power. In this report, they study the use of amorphic diamond films as photoconductive switch coatings to enhance the longevity and operation. Semiconductor properties of amorphic diamond relevant to high and low power switch applications are discussed.