Optically-initiated silicon carbide high voltage switch
View Patent ↗An improved photoconductive switch having a SIC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.
1. A photoconductive switch comprising:
a photoconductive substrate composed of a greater-than-1.6 eV wide band gap material, said substrate having at least one concavity(s), and a facet optically connectable to an optical source so as to receive optical energy therefrom; and
two electrodes electrically connected to the substrate with at least one of the electrodes having a convex surface contactedly seated in a corresponding one of the at least one concavity(s) so as to apply a potential across the substrate.
2. The photoconductive switch of claim 1 ,
wherein the substrate is a multilayer having at least two photoconductive layers separated by a divider layer.
3. The photoconductive switch of claim 2 ,
wherein the divider layer is selected from a group consisting of conductive and semi-conductive materials.
4. The photoconductive switch of claim 1 ,
wherein the substrate is a compensated, semi-insulating material selected from a group consisting of 4 h SiC, 6 h SiC, and GaN.
5. The photoconductive switch of claim 4 ,
wherein the substrate is semi-insulating SiC having a hexagonal crystal structure and cut in a plane selected from the group consisting of the A-Plane, C-Plane and M-plane.
6. A photoconductive switch comprising:
a photoconductive substrate composed of a greater-than-1.6 eV wide band gap material, said substrate having at least one concavity(s), and a facet optically connectable to an optical source for receiving optical energy therefrom; and
two electrodes electrically connected to the substrate with at least one of the electrodes having a convex surface contactedly seated in a corresponding one of the at least one concavity(s), for applying a potential across the substrate,
wherein the substrate comprises at least two layers cut in the C-Plane and offset from each other.
7. The photoconductive switch of claim 4 ,
wherein the semi-insulating SiC is doped with at least one of the following dopants: Boron, Vanadium, Nitrogen, Aluminum, Phosphorus, Oxygen, Tungsten and Zinc.
8. The photoconductive switch of claim 1 ,
wherein at least one facet of the substrate is coated with a dielectric to produce total internal reflection.