Figure 1.

The scheme of fabricating axial pn junction Si NWs—a An as-grown pi NW b scanning electron microscope (SEM) image of an as-grown pi NW. c A NW with the Au cap removed d SEM image of a NW with the Au cap removed. e P ion implantation on a NW coated with the spin-on-glass (SOG) silicon dioxide. The top intrinsic part is converted to n-type f SEM image of an SOG-coated NW. g Apn junction NW after the P ion implantation and removal of the SOG. h SEM image of a pn junction NW

Kanungo et al. Nanoscale Research Letters 2009 5:243-246   doi:10.1007/s11671-009-9472-x