New low-resistance contacts pave way for improved gallium nitride semiconductor devices

Semiconductor devices such as LEDs and transistors generally consist of two halves: an n-type, which carries negative charge via electrons, and a p-type, which moves positive charge carriers called holes that are essentially electron voids. Both halves rely on contacts that allow electric current to flow in and out with minimal energy loss. These connections, known as ohmic contacts, have been an efficiency bottleneck in thin p-type GaN semiconductors for decades because of their high resistance.