  The synthesis of one-dimensional van der Waals heterostructures was realized
recently, which opens up new possibilities for prospective applications in
electronics and optoelectronics. The even reduced dimension will enable novel
properties and further miniaturization beyond the capabilities of its
two-dimensional counterparts have revealed. The natural doping results in
p-type electrical characteristics for semiconducting single-walled carbon
nanotubes, while n-type for molybdenum disulfide with conventional noble metal
contacts. Therefore, we demonstrate here a one-dimensional heterostructure
nanotube of 11-nm-wide, with the coaxial assembly of semiconducting
single-walled carbon nanotube, insulating boron nitride nanotube, and
semiconducting molybdenum disulfide nanotube which induces a radial
semiconductor-insulator-semiconductor heterojunction. When opposite potential
polarity was applied on semiconducting single-walled carbon nanotube and
molybdenum disulfide nanotube, respectively, the rectifying effect was
materialized.
