Resolving carrier concentration of n-type AlN/GaN nanowires by scanning spreading resistance microscopy

The AlN/GaN nanowire structures hold significant promising for enhancing the emission efficiency of ultraviolet light-emitting diodes. However, their electrical doping mechanisms remain insufficiently understood and require indepth investigation. Scanning spreading resistance microscopy (SSRM) was performed to systematically investigate the dopant distribution of Si-doped AlN/GaN nanowires (NWs) grown by plasma-assisted molecular beam epitaxy with Si cell temperatures ranging from 800 to 1000 °C. To ensure sample flatness at different NWs length, the NWs were embedded in a sol gel silica, and samples were subsequently polished in order to obtain a beveled profile. The nanowires doping trends were extracted from the SSRM data by deconvolution of silica and NWs responses. These studies demonstrated the axial uniformity and the radial uniformity of the NW core of Si.