Gas sensor made of graphene-tungsten disulfide composite material and preparation method of gas sensor

Abstract

The invention discloses a graphene-tungsten disulfide composite material gas sensor which sequentially comprises a silicon substrate layer, a silicon dioxide insulating layer, an electrode layer, a graphene layer and a tungsten disulfide layer from bottom to top, the silicon dioxide insulating layer covers the upper surface of the silicon substrate layer, the electrode layer is arranged on the surface of the silicon dioxide insulating layer, and the graphene layer is arranged on the surface of the tungsten disulfide layer. The electrode layer comprises a gear shaping electrode and large electrodes, the large electrodes are located at the two ends of the gear shaping electrode, the graphene layer is single-layer graphene and covers the surface of the gear shaping electrode, the thickness of the tungsten disulfide layer is smaller than 10 nm, and the tungsten disulfide layer is arranged on the surface of the graphene layer. Graphene and tungsten disulfide are compounded to form a composite material as a gas-sensitive material, tungsten disulfide makes up for the defect that the band gap of graphene is zero, graphene makes up for the defect that layered stacking is likely to be caused in an electrical test after tungsten disulfide adsorbs gas, and the two materials complement each other in advantages to improve the sensitivity of the sensor.

Description

technical field [0001] The invention belongs to the technical field of micro-electromechanical systems (MEMS) gas sensor chips, and particularly relates to a graphene-tungsten disulfide composite material gas sensor and a preparation method thereof. Background technique [0002] In 2004, British scientist Andre Geim and others used the micromechanical exfoliation method to prepare single-layer graphene, which opened the curtain of graphene research. Graphene has excellent physical and chemical properties, such as graphene's Young's modulus of 1.1 TPa and a tensile strength of 130 Gpa, in addition to its good light transmittance and negative thermal expansion coefficient. In terms of electricity, graphene has a good bipolar electric field effect, and can exhibit N-type or P-type characteristics under the action of external voltage, and its carrier mobility reaches 10,000-15,000 cm2V-1s-1. At present, the preparation methods of graphene are also endless, including micromechan...

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Problems solved by technology

As one of them, tungsten disulfide also has the advantages of gas detection, but in the process of forming a conductive network inside it, it is easy to form a dense layered stacked structure, which is not conducive to the contact between nanosheets and gas molecules.

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