Group iii nitride vertical photoconductive semiconductor switch

A photoconductive semiconductor switch triggered by irradiation of focused light or laser light comprising

• (a) a plate of a semi-insulating group III nitride crystal having a top surface and a bottom surface,
• (b) a bottom electrode on the bottom surface;
• (c) a photo-active electrically conductive region inside the plate and exposed to the top surface,
• (d) a top electrode electrically connected to the electrically conductive region,
• wherein a first shortest distance from an edge of the top surface to an adjacent boundary of the electrically conductive region is more than a thickness of the plate, a second shortest distance from the edge of the top surface to the top electrode is more than the thickness of the plate, and the top electrode has a surface area on the electrically conductive region that is less than 10% of a surface area of the electrically conductive region.