Engineering Commons^™

Investigating Operational Modes In Gallium Nitride Photoconductive Switches, Brad J. Maynard

Electrical and Computer Engineering ETDs

As switching requirements for speed, power, and efficiency become more stringent, advances in wide-bandgap (WBG) materials has enabled their use in high power switching devices. One such device, the photoconductive semiconductor switch (PCSS), while previously constructed from GaAs, shows promise using WBG Mn-doped GaN. Lateral and vertical geometries of PCSS have been produced and evaluated for operation using sub-mJ/ns regime pulsed laser incidence. At fields below 25 kV/cm, the lateral switch operates in the linear regime where modest photocurrent fitting the laser envelope is observed. Above this threshold, the switches demonstrate circuit-limited persistent conductivity (PC) current, in what is presumed …

Etched-And-Regrown Diodes On M-Plane Gan For Next Generation Power Electronic Devices, Andrew A. Aragon

Electrical and Computer Engineering ETDs

Demand for next-generation power electronic devices is driven by continually evolving requirements of power systems. Devices utilizing III-nitride materials (GaN) and vertical selective-area doped architectures are advantageous due to their wide- bandgap, thermal management, small form-factor, and current handling.

Such devices incorporate junctions at multiple crystalline planes. Thus, effects of impurity contamination and etch damage are investigated on the m-plane (10-10) of GaN. Impurites (Si, O, and C) are shown to reduce blocking voltage (~ 10² ×) and increase forward leakage current (~ 10⁴ ×) in regrown versus continuously-grown p-n diodes. Elevated deep level defects at Ec – …