Orientation-controlled alignment of axially modulated pn silicon nanowires.

We demonstrate orientation-controlled alignment of axially modulated pn SiNWs by applying dc electric fields across metal electrodes. The as-aligned pn SiNWs exhibit rectifying behaviors with a 97.7% yield, and about 35% of them exhibit no hysteresis in their current-voltage curves that can be directly used to construct AND/OR logic gates. Moreover, the as-aligned pn SiNWs can be packaged either with polydimethylsiloxane or additional metal layer to protect and even improve the quality of these NW diodes.