CHEMORESISTIVE GAS SENSOR AND METHOD FOR ITS MANUFACTURE Russian patent published in 2023 - IPC G01N27/12 B82Y30/00 B82Y40/00 

FIELD: measurement equipment.

SUBSTANCE: chemoresistive gas sensor contains a dielectric substrate with measuring electrodes located on one side of the substrate, and their contact pads are configured to be connected to the measuring device using contact conductors. The sensor also contains a metal heater configured to provide uniform heating over the entire surface of the substrate, located on the other side of the substrate. The surface of the substrate containing the electrodes is covered with a gas-sensitive layer consisting of porous silicon nanorods and zinc oxide nanorods, and the measuring electrodes are made in the form of interdigitated electrodes. The method for manufacturing chemoresistive gas sensors of the design described above involves applying a gas-sensitive layer, for formation of which a layer of zinc oxide nanoparticles is used. For this purpose, it is placed in a solution containing zinc cations and hydroxide ions in equal proportions, and kept at an elevated temperature. Then the substrate with the formed gas-sensitive layer of zinc oxide nanorods is washed with distilled water, dried at room temperature, and annealed. To grow a gas-sensitive layer, a single-crystal silicon plate of electronic conductivity type with crystallographic orientation (111) is placed in an aqueous-alcohol solution of HF with simultaneous deposition of Ag nanoparticles from an aqueous solution of AgNO₃ and electrochemical etching of porous silicon with Ag nanoparticles is carried out in an aqueous-alcohol solution of HF. Next, post-treatment is carried out in an aqueous solution of HNO₃, alcohol, and distilled H₂O. Next, a layer of zinc oxide nanoparticles is applied to the resulting layer of porous silicon nanorods and annealed. The said process of applying a layer of zinc oxide nanoparticles followed by annealing is repeated at least twice. Zinc oxide nanorods are grown on the surface of zinc oxide nanoparticles using the hydrothermal method. The resulting hybrid layer is washed with distilled water, dried and annealed. The resulting layer is transferred over the electrodes, a heater is applied using the spin-coating method in such a way that it provides heating of the entire surface of the substrate, and annealed.

EFFECT: improved sensitivity.

2 cl, 4 dwg