Korea University Research and Business Foundation

Samsung Electronics Co., Ltd.

The Electro-mechanics Company

Jong-Heun Lee

Tae-young Kim

Tae-Hyung Kim

Jae-myung Lee

Kyo-yeol Lee

Young-sin Park

Seung-wook Baek

Jee-Uk Yoon

Ho-in Kim

Yunchan Kang

Hyung-Sik Woo

Ji-Wook Yoon

Byung-ki Kim

Hyun-Mook Jeong

Hyo-Joong Kim

Su-Jin Hwang

Jee-hyun Ahn

Jae-Hyeok Kim

Provided is an oxide semiconductor gas sensor with improved performance that senses selectively methylbenzene gases with high sensitivity. The gas sensor includes a gas sensing layer composed of palladium (Pd)-loaded cobalt oxide (CoO) nanostructures. The response of the gas sensor according to the present invention to xylene gas at a concentration as low as 5 ppm is at least 150 times higher than that to ethanol gas. The response of the gas sensor to toluene gas at a concentration as low as 5 ppm is at least 100 times higher than that to ethanol gas. In addition, the oxide semiconductor gas sensor has the ability to selectively detect methylbenzene gases, including xylene and toluene (with at least 30-fold higher response to xylene and at least 15 times higher response to toluene than that to ethanol gas).

Methylbenzene gas sensor using palladium-containing cobalt oxide nanostructures and method for manufacturing the same

Disclosed is a gas sensing material for methylbenzene detection. Specifically, the gas sensing material includes a nanocomposite of CrOand ZnCrO. The content of Cr in the nanocomposite is from 67.0 at. % to 90.0 at. %, based on the sum of the contents of Cr and Zn atoms. The gas sensing material is highly selective to methylbenzenes over other gases and is highly sensitive to methylbenzenes. Also disclosed are methods for preparing the gas sensing material. The methods facilitate control over the composition of the gas sensing material and enable rapid synthesis of the gas sensing material at low temperature. Also disclosed is a gas sensor including the gas sensing material.

Highly sensitive and selective gas sensing material to methylbenzene, methods for preparing the gas sensing material and gas sensor including the gas sensing material

Provided is a gas sensor comprising a gas-sensitive layer consisting of nickel oxide (NiO) doped with chrome (Cr) so as to selectively detect methylbenzene gas. The gas sensor, according to the present invention, has a gas-sensitive layer consisting of Cr-doped NiO. The gas sensor exhibits superior selectivity for methylbenzene gas when compared to other gases. The gas sensor can be easily and mass produced according to the production method of the present invention and is not affected by the microstructures of the material forming the gas-sensitive layer. The present invention relates to a gas sensor exhibits a negligible sensitivity of benzene, formaldehyde, and alcohol and exhibits significantly high selectivity and sensitivity of methylbenzene gas such as xylene and toluene when the NiO sensor material with a hierarchical structure favorable to gas dispersion and response is doped with Cr.

Methylbenzene gas sensor using chrome-doped nickel oxide nanostructures and method for producing same

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Solid ion conductor, solid electrolyte including the same, lithium battery including the solid electrolyte, and method of manufacturing the solid ion conductor

An air-to-fuel (A/F) ratio sensor includes an insulation layer, two solid electrolyte layers made of a porous composite ceramic formed at both sides of the insulation layer, each solid electrolyte layer having an internal electrode layer on its boundary surface with the insulation layer and an external electrode layer on its other surface, and a diffusion barrier layer made of a porous composite ceramic, covering one of the external electrode layers. The A/F ratio sensor provides a linear A/F ratio signal by controlling only a pumping current for a reference partial pressure of oxygen. Thus, the A/F ratio sensor operates by a simpler driving principle, thereby simplifying the driving circuit thereof.

Air-to-fuel ratio sensor

A planar air-to-fuel (A/F) ratio sensor and a driving circuit therefor are provided. A circuit for driving a planar A/F ratio sensor having a structure wherein an exhaust gas side electrode is shared by a pumping cell and a sensing sell, or a structure wherein an air side electrode is shared by the pumping cell and the sensing cell, is comprised of a comparator for comparing a voltage measured in the sensing cell with a predetermined reference voltage corresponding to the voltage the sensing cell when the pumping cell is within a limit current range to output a voltage which is proportional to the difference between two compared voltages, an integrator for integrating the output of the voltage comparator to output a voltage, an adder for adding a voltage for compensating an electromotive force of the pumping cell to the output voltage of the integrator and an A/F ratio detector for sensing the current flowing through the pumping cell from a voltage output from the adder and applied to the pumping cell to detect an A/F ratio. Therefore, damage to the electrode can be prevented, and the response characteristic between the sensing cell and pumping cell and the accuracy in measuring the A/F ratio can be improved. Also, shift of the current limit region into a region where a voltage V.sub.p is greater than 0 can be compensated by an internal electromotive force of the pumping cell.

Planar air-to fuel ratio sensor and driving circuit therefor

Growing community of inventors

Seoul, South Korea

Jong-Heun Lee