Structural and Electrical Transport Properties of Si doped GaN nanowires

The control and assessment of doping in GaN nanostructures are crucial for the realization of GaN based nanodevices. In this study, we have investigated a series of Si-doped GaN nanowires (NWs) grown by molecular beam epitaxy (MBE) with a typical dimension of 2-3 μm in length, and 20-200 nm in radius. In particular, high resolution energy dispersive X-ray spectroscopy (EDX) has illustrated a higher Si incorporation in NWs than that in two-dimensional (2D) layers and Si segregation at the edge of the NW with the highest doping. Moreover, direct transport measurements on single NWs have revealed a controlled doping with resistivity from 2 × 10
^-2
to 10
^-3
Ω.cm for Si doped NWs. Field effect transistor (FET) measurements combined with finite element simulation have shown the high mobility of carriers in the non-intentionally doped (NID) NWs.