TY  - JOUR
AU  - Li, Xiaohui
AU  - Du, Ruofan
AU  - Luo, Quankun
AU  - Feng, Wang
AU  - Yang, Junbo
AU  - Song, Luying
AU  - Wen, Xia
AU  - Peng, Yanan
AU  - Jiang, Yulin
AU  - Sun, Hang
AU  - Huang, Ling
AU  - Li, Hui
AU  - Xiao, Mengmeng
AU  - He, Jun
AU  - Shi, Jianping
PY  - 2025
TI  - Uniform epitaxy and controllable iron doping of centimeter-size bilayer tungsten disulfide with unidirectional alignment
JO  - Nano Research
SN  - 1998-0124
SP  - 94907694
VL  - 18
IS  - 9
AB  - 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.
UR  - https://doi.org/10.26599/NR.2025.94907694
DO  - 10.26599/NR.2025.94907694