Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage
Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage
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DOI：
10.1021/acsnano.5b01341
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发表时间：
2015-07-01
期刊：
影响因子：
17.1
通讯作者：
Hone, James
中科院分区：
文献类型：
--
作者：
Lee, Gwan-Hyoung;Cui, Xu;Hone, James
由于其用于晚期电子产品和光电子学的新颖性，已经对出现的二维（2D）半导体（例如钼）（MOS2）进行了深入研究。然而，二维材料本质上对环境影响敏感，例如温度，湿度，吸附物和邻近介电中的被困电荷。因此，开发提供高性能和长期稳定性的设备体系结构至关重要。在这里，我们报告了双门控范德华（VDW）异质结构设备的高性能，其中MOS2层被六角形硝酸硼（HBN）完全封装，并使用石墨烯形成了触点。 HBN包容性为环境因素提供了极大的保护，即使在升高的温度下，也会产生高度稳定的设备性能。我们的测量值还显示出高质量的电触点和滞后降低，导致高两个末端载流子迁移率（33-151 cm（2）V-1 S（-1））和室温下低下阈值摆动（80 mV/dec）。此外，对石墨烯费米水平的调整以及双门门的使用使我们能够分别控制接触电阻和阈值电压。这款新型VDW异质结构设备为基于2D材料制造稳定的高性能设备的新方法开辟了新的方法。
Emerging two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. However, 2D materials are by nature sensitive to environmental influences, such as temperature, humidity, adsorbates, and trapped charges in neighboring dielectrics. Therefore, it is crucial to develop device architectures that provide both high performance and long-term stability. Here we report high performance of dual-gated van der Waals (vdW) heterostructure devices in which MoS2 layers are fully encapsulated by hexagonal boron nitride (hBN) and contacts are formed using graphene. The hBN-encapsulation provides excellent protection from environmental factors, resulting in highly stable device performance, even at elevated temperatures. Our measurements also reveal high-quality electrical contacts and reduced hysteresis, leading to high two-terminal carrier mobility (33-151 cm(2) V-1 s(-1)) and low subthreshold swing (80 mV/dec) at room temperature. Furthermore, adjustment of graphene Fermi level and use of dual gates enable us to separately control contact resistance and threshold voltage. This novel vdW heterostructure device opens up a new way toward fabrication of stable, high-performance devices based on 2D materials.