Negative rectification and negative differential resistance in nanoscale single-walled carbon nanotube p-n junctions

We investigate the transport properties of few-nm-long single-walled carbon nanotube (SWCNT) p-n junctions for the first time by using ab initio quantum transport calculations. Unlike the previously reported few-μm-long SWCNT p-n junctions, which rectify positively, all the investigated ultrashort SWCNT p-n junctions show negative rectification effect, accompanied by negative differential resistance.