"The most vocal champion of the GaN revolution is Alex Lidow, a physicist and chief executive officer of Efficient Power Conversion (EPC) in El Segundo, Calif. Lidow, 60, has spent much of his career seeking a material that can perform operations faster and survive harsher conditions than silicon. Over the past two decades, he and dozens of other scientists have toiled to take GaN transistors from the experimental stage to the point where they can be produced at standard semiconductor manufacturing plants. EPC’s transistors are in only a handful of products. But over the past 18 months, production methods have improved enough for the technology to go more mainstream."

http://epc-co.com/epc/FAQ/eGaNTechnology.aspx

"Is it also possible to produce p-channel enhancement mode GaN transistors?

Enhancement mode and depletion mode n-channel GaN devices are available on the market today. EPC supplies only enhancement mode n-channel devices at the present time. Whereas it is possible to make a p-channel device, the performance is quite poor compared with silicon. For a preview of EPC’s technology roadmap, watch the video “How to GaN 11: A Look into the Future”. You can also sign up to receive news and product updates from EPC at http://bit.ly/EPCupdates or by texting "EPC" to 22828."