Optimization of Deposition Conditions to Grow High-Quality Fe–Se–Te Thin Films

High-performance Fe–Se–Te (FST) films are favorable for revealing the relationships between the crystal structure and the superconducting properties of the material because of their simple structures. Therefore, it is particularly important to prepare high-quality “11” thin films. Herein, we focused on the thickness and deposition temperature dependence of $T^{\rm {zero}}_{\rm{c}}$ and found that the thickness of about 200 nm and the deposition temperature of 300 °C are the optimal parameters for growing high-quality FST films on CaF2 and SrTiO3 substrates, which exhibit $T^{\rm {zero}}_{\rm{c}}$ of 18.8 K and 17 K, respectively. Magnetic Jc values of FST films grown on CaF2 and SrTiO 3 are both larger than 2 × 106 A·cm–2 at 4.2 K and self-field, significantly higher than that of FST single crystals.