@article{Li2025, 
author = {Xiaohui Li and Ruofan Du and Quankun Luo and Wang Feng and Junbo Yang and Luying Song and Xia Wen and Yanan Peng and Yulin Jiang and Hang Sun and Ling Huang and Hui Li and Mengmeng Xiao and Jun He and Jianping Shi},
title = {Uniform epitaxy and controllable iron doping of centimeter-size bilayer tungsten disulfide with unidirectional alignment},
year = {2025},
journal = {Nano Research},
volume = {18},
number = {9},
pages = {94907694},
keywords = {Schottky barrier width, centimeter-size uniform, bilayer tungsten disulfide, unidirectional domain orientation, ultrahigh electron mobility},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907694},
doi = {10.26599/NR.2025.94907694},
abstract = {Bilayer transition-metal dichalcogenides (TMDCs) are promising channel materials for state-of-the-art transistors, due to their smaller bandgap, higher carrier mobility, and better electrostatic control than those of the monolayer counterparts. Epitaxial growth and controllable doping of wafer-scale bilayer TMDCs single crystals are two pivotal tasks to meet the practical applications of high-performance electronic devices. Despite considerable efforts have been made, addressing such fundamental issues simultaneously has yet to be realized. Here we design an ingenious Fe-assisted epitaxial strategy to synthesize centimeter-size uniform bilayer tungsten disulfide (WS2) with unidirectional alignment on industry-compatible c-plane sapphire. The introduction of Fe promotes the formation of parallel steps on sapphire surfaces to induce the edge-nucleation of unidirectionally aligned bilayer WS2 and the evolution of centimeter-size uniform films. The ionic liquid gated transistors with ultrahigh electron mobility (169 cm2·V−1·s−1) and remarkable on/off current ratio (108) are constructed based on the centimeter-size bilayer Fe-WS2, due to the reduction of Schottky barrier width induced by Fe doping. This work provides a simple and general approach for synthesizing and doping of wafer-scale bilayer TMDCs, which should accelerate the further device downscaling to extend Moore’s law.}
}