Deagueros Julian Ignacio, Gao Min, Cai Alice, Li Xiaotong, Ulaganathan Rajesh Kumar, Mani Shankar, Sankar Raman, Ishida Hatsuo, Gao Xuan P A
Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, United States.
Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India.
ACS Appl Mater Interfaces. 2025 Jun 18;17(24):35723-35731. doi: 10.1021/acsami.5c04399. Epub 2025 Jun 6.
Heterostructures made from 2D materials have led to the discovery of many new electronic phases and have the potential for electronic devices with better performance. However, the mechanism by which charge is transferred or distributed in these novel heterostructure devices made of atomically thin semiconductors is yet to be fully understood. By creating and electronically characterizing InSe/GaS heterostructure field-effect transistors with different metal contact configurations, we observed a decrease in the maximum on-current and an increase in the hysteresis when both the InSe and GaS layers are in contact with the metal contacts. This, combined with the time-dependent conductance decay measurements, suggests that charge flow into the GaS from the metal contacts is the source of the hysteresis, which can be mitigated by encapsulating the GaS with InSe. Our resultant nearly hysteresis-free devices exhibit an average field-effect mobility of 34 ± 8 cmVs at room temperature, comparable to that of bare InSe of the same size, with an average n-type modulation doping of ∼ 1 × 10 cm from the GaS layer.
由二维材料制成的异质结构已促成许多新电子相的发现，并具有制造性能更优电子器件的潜力。然而，在这些由原子级薄半导体构成的新型异质结构器件中，电荷转移或分布的机制尚未完全明晰。通过制备具有不同金属接触配置的InSe/GaS异质结构场效应晶体管并对其进行电学表征，我们观察到，当InSe层和GaS层均与金属接触时，最大导通电流减小，滞后现象增加。结合随时间变化的电导衰减测量结果表明，从金属接触流入GaS的电荷是滞后现象的根源，通过用InSe包裹GaS可以减轻这种现象。我们最终得到的几乎无滞后的器件在室温下表现出34±8 cm²V⁻¹s⁻¹的平均场效应迁移率，与相同尺寸的裸InSe相当，且来自GaS层的平均n型调制掺杂约为1×10¹³ cm⁻³。
