Gas sensor based on TMDCs-SFOI heterojunction and preparation method thereof

Abstract

The invention provides a gas sensor based on TMDCs-SFOI heterojunction and a preparation method thereof. The gas sensor takes two-dimensional transition metal sulfide TMDCs as a gas sensitive layer and a semiconductor film on an insulator SFOI as a conductive channel; after TMDCs are contacted with SFOI, due to the Fermi level difference, electrons are transferred from the high Fermi level side tothe low Fermi level side, thereby generating space charge regions on both sides of the heterojunction and forming a p-n junction; when gas molecules to be detected are adsorbed on the surface of theTMDCs and charge transfer occurs between the gas molecules to be detected and the TMDCs, the concentration of carriers in the TMDCs is changed, a p-n junction potential barrier is changed, the width of the space charge region in the SFOI is changed, and finally the resistance of the conductive channel is changed, so that the gas to be detected is sensed. According to the gas sensor based on TMDCs-SFOI heterojunction and the preparation method thereof, the gas sensitive layer is separated from the conductive channel, meanwhile, the high sensitivity of the two-dimensional TMDCs to adsorbed gas molecules is utilized, and a gas detector is beneficial to achieving high sensitivity and high reliability and can be directly integrated on a semiconductor chip together with the mature traditional semiconductor device process.

Description

technical field [0001] The invention belongs to the technical field of gas sensors, and more specifically, relates to a gas sensor based on a TMDCs-SFOI heterojunction and a preparation method thereof, wherein the heterojunction structure consists of two-dimensional transition metal sulfides (TMDCs) and an insulator A heterojunction formed by Semiconductor Films On Insulators (SFOI). Background technique [0002] A gas sensor is a device or device that can sense a certain gas and its concentration in the environment. It can convert information related to the type and concentration of the gas into electrical, optical, and acoustic signals that can be directly read and quantified by the device. In order to detect, monitor, analyze, alarm, etc. In recent decades, gas sensors have been widely used in industrial production, environmental monitoring, medicine and health and other fields. According to the detection principle, gas sensors can be divided into electrical, optical, e...

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Problems solved by technology

[0007] In view of the above shortcomings or improvement needs of the prior art, the purpose of the present invention is to provide a gas sensor based on TMDCs-SFOI heterojunction and its preparation method, which can effectively solve the problem that the TMDCs gas sensor is greatly affected by surface scattering compared with the prior art. , poor stability, susceptible to interference and other issues, the gas sensor in the present invention uses TMDCs as the gas sensitive layer, and SFOI as the conductive channel; after TMDCs and SFOI are in contact, due to the difference in the Fermi level between each other, electrons from high to low One side of the Fermi level is transferred to the side of the lower Fermi level, thereby generating a space charge region on both sides of the heterojunction to form a p-n junction; when the gas molecules to be measured are adsorbed on the surface of TMDCs and undergo charge transfer with TMDCs , the carrier concentration in TMDCs changes, causing changes in the p-n junction barrier, resulting in changes in the width of the space charge region in SFOI, and finally changes in the resistance of the conductive channel to realize the sensing of gas molecules

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