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Strain-Gated Field Effect Transistor of a MoS2–ZnO 2D–1D Hybrid Structure

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journal contribution
posted on 26.01.2016, 00:00 by Libo Chen, Fei Xue, Xiaohui Li, Xin Huang, Longfei Wang, Jinzong Kou, Zhong Lin Wang
Two-dimensional (2D) molybdenum disulfide (MoS2) is an exciting material due to its unique electrical, optical, and piezoelectric properties. Owing to an intrinsic band gap of 1.2–1.9 eV, monolayer or a-few-layer MoS2 is used for fabricating field effect transistors (FETs) with high electron mobility and on/off ratio. However, the traditional FETs are controlled by an externally supplied gate voltage, which may not be sensitive enough to directly interface with a mechanical stimulus for applications in electronic skin. Here we report a type of top-pressure/force-gated field effect transistors (PGFETs) based on a hybrid structure of a 2D MoS2 flake and 1D ZnO nanowire (NW) array. Once an external pressure is applied, the piezoelectric polarization charges created at the tips of ZnO NWs grown on MoS2 act as a gate voltage to tune/control the source–drain transport property in MoS2. At a 6.25 MPa applied stimulus on a packaged device, the source–drain current can be tuned for ∼25%, equivalent to the results of applying an extra −5 V back gate voltage. Another type of PGFET with a dielectric layer (Al2O3) sandwiched between MoS2 and ZnO also shows consistent results. A theoretical model is proposed to interpret the received data. This study sets the foundation for applying the 2D material-based FETs in the field of artificial intelligence.