Chemical Vapor Deposition of Superconducting FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> Nanosheets.

Hu, Dianyi; Ye, Chen; Wang, Xiaowei; Zhao, Xiaoxu; Kang, Lixing; Liu, Jiawei; Duan, Ruihuan; Cao, Xun et al. · Nano Lett · 2021

basic_science · Level V

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Abstract

FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub>, 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 FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> 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 FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> superconductor by a facile, atmospheric pressure chemical vapor deposition (CVD) method. The composition and thickness of the two-dimensional (2D) FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> nanosheets are well controlled by tuning the experimental conditions. The as-prepared FeTe<sub>0.8</sub>Se<sub>0.2</sub> 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 FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> superconductor, which could become a promising platform for further study of the unconventional superconductivity in the FeTe<sub>1-<i>x</i></sub>Se<sub><i>x</i></sub> system.