van der Waals Self-Epitaxial Growth of Inch-Sized Superconducting Niobium Diselenide Films
Liang Ma, Xiaohan Wang, Hao Wang, Xiangyi Wang, Guifu Zou, Yanqiu Guan, Shuya Guo, Haochen Li, Qi Chen, Lin Kang, Labao Zhang, Peiheng Wu
Abstract
Ultrathin superconducting films are the basis of superconductor devices. van der Waals (vdW) NbSe 2 with noncentrosymmetry exhibits exotic superconductivity and shows promise in superconductor electronic devices. However, the growth of inch-scale NbSe 2 films with layer regulation remains a challenge because vdW structural material growth is strongly dependent on the epitaxial guidance of the substrate. Herein, a vdW self-epitaxy strategy is developed to eliminate the substrate driving force in film growth and realize inch-sized NbSe 2 film growth with thicknesses from 2.1 to 12.1 nm on arbitrary substrates. The superconducting transition temperature of 5.1 K and superconducting transition width of 0.30 K prove the top homogeneity and quality of superconductivity among all of the synthetic NbSe 2 films. Coupled with a large area and substrate compatibility, this work paves the way for developing NbSe 2 superconductor electronics.