TY - JOUR
T1 - Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage
AU - Lee, Gwan Hyoung
AU - Cui, Xu
AU - Kim, Young Duck
AU - Arefe, Ghidewon
AU - Zhang, Xian
AU - Lee, Chul Ho
AU - Ye, Fan
AU - Watanabe, Kenji
AU - Taniguchi, Takashi
AU - Kim, Philip
AU - Hone, James
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/7/28
Y1 - 2015/7/28
N2 - 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 cm2 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.
AB - 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 cm2 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.
KW - MoS
KW - contact resistance
KW - graphene
KW - hexagonal boron nitride
KW - threshold voltage
KW - two-dimensional materials
KW - van der Waals heterostructure
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U2 - 10.1021/acsnano.5b01341
DO - 10.1021/acsnano.5b01341
M3 - Article
AN - SCOPUS:84938118601
SN - 1936-0851
VL - 9
SP - 7019
EP - 7026
JO - ACS Nano
JF - ACS Nano
IS - 7
ER -