Chemical Vapor Deposition of Superconducting FeTeSe Nanosheets.

FeTeSe, a promising layered material used to realize Majorana zero modes, has attracted enormous attention in recent years. Pulsed laser deposition (PLD) and molecular-beam epitaxy (MBE) are the routine growth methods used to prepare FeTeSe thin films. However, both methods require high-vacuum conditions and polished crystalline substrates, which hinder the exploration of the topological superconductivity and related nanodevices of this material. Here we demonstrate the growth of the ultrathin FeTeSe superconductor by a facile, atmospheric pressure chemical vapor deposition (CVD) method. The composition and thickness of the two-dimensional (2D) FeTeSe nanosheets are well controlled by tuning the experimental conditions. The as-prepared FeTeSe nanosheet exhibits an onset superconducting transition temperature of 12.4 K, proving its high quality. Our work offers an effective strategy for preparing the ultrathin FeTeSe superconductor, which could become a promising platform for further study of the unconventional superconductivity in the FeTeSe system.