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 m...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(WS_(2))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 WS_(2)and the evolution of centimeter-size uniform films.The ionic liquid gated transistors with ultrahigh electron mobility(169 cm^(2)·V^(-1)·s^(-1))and remarkable on/off current ratio(10^(8))are constructed based on the centimeter-size bilayer Fe-WS_(2),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.展开更多
基金supported by the National Key R&D Program of China(No.2021YFA1200800)the National Natural Science Foundation of China(Nos.U24A2055, 92164103)+2 种基金the Natural Science Foundation of Hubei Province(No.2024AFA052)Wuhan Science and Technology Bureau(Knowledge Innovation Program of Wuhan-Basic Research,No.2023010201010067)the Fundamental Research Funds for the Central Universities(No.2042023kf0187)。
文摘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(WS_(2))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 WS_(2)and the evolution of centimeter-size uniform films.The ionic liquid gated transistors with ultrahigh electron mobility(169 cm^(2)·V^(-1)·s^(-1))and remarkable on/off current ratio(10^(8))are constructed based on the centimeter-size bilayer Fe-WS_(2),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.
