Introducing the spiked p-n junction for tunnel devices and current gain

By serendipity, a novel feature has appeared in regrown GaN p-n junctions. When the device is exposed to atmosphere in between the growth of the n and p regions, a sheet layer of donors (primarily oxygen) incorporates at the junction interface [1,2]. This has been argued to decrease the depletion width, which boosts tunneling currents to acceptable levels for contacts to GaN LEDs [1].