Carrier confinement in nanowire (NW) structures can offer a host of new material properties compared to bulk electronic devices. Diamond can be considered an ultimate semiconductor given its superlative electronic, physical, and optical properties. However, the development of diamond device technology has been hindered by doping problems in conventional device structures. Here, heavily doped diamond NWs, some 15 nm wide and only 1–2 nm deep overcome these issues and offer a significant advance in NW technology; transistor action can be induced with remote side gates alone, without the need for semiconductor junctions. Quasi-ballistic transport is most-likely responsible for extraordinary current handling capability of the NW transistors fabricated here at some 20 MA cm−2, being around 0.04 G0. This unipolar technology opens up a new paradigm in diamond nanoelectronic device technology
