  A lateral heterojunction of topological insulator Sb2Te3/Bi2Te3 was
successfully synthesized using a two-step solvothermal method. The two
crystalline components were separated well by a sharp lattice-matched interface
when the optimized procedure was used. Inspecting the heterojunction using
high-resolution transmission electron microscopy showed that epitaxial growth
occurred along the horizontal plane. A rectification curve was observed at low
temperatures. Quantum correction from the weak antilocalization reveals the
transport of the topological surface state. There was, therefore, a
staggered-gap lateral heterojunction with a small junction voltage, which is
appealing for a platform for spin filters and one-dimensional topological
interface states.
