▲From left, Dr. Jinwoo Choi of the Korea Institute of Materials Science, Dr. Hanseul Kim of the Korea Institute of Science and Technology Information, and Professor Hyeongwoo Lee of Pusan National University (Photo source: Korea Institute of Materials Science)


Development of the world's first multi-response high-selectivity gas sensor
Suitable for lightweight and miniaturization, highly usable in the 4th industrial revolution

A domestic research team has discovered a material whose crystal structure can change when exposed to a specific gas, and based on this, developed a sensor that changes both color and resistance, bringing the country one step closer to domestic production of semiconductor sensor technology.

The research team of Dr. Jinwoo Choi from the Energy and Electronic Materials Laboratory of the Korea Institute of Materials Science (hereafter, MATERIALS), Dr. Hanseul Kim from the Korea Institute of Science and Technology Information (hereafter, KISTI), and Professor Hyeongwoo Lee from Pusan National University announced on the 4th that they have succeeded in developing the world's first multi-response high-selectivity gas sensor capable of simultaneous optical and electrical measurements by elucidating the reaction principle of a high-selectivity gas sensor material through joint research.

A gas sensor is an electronic device used to measure the concentration of various gases.

Existing semiconductor gas sensor materials detect gas through changes in electrical resistance when gas is adsorbed on the surface.

Since the resistance changes regardless of the gas type, the selectivity is low, and most of them use only a single indicator of electrical characteristic change, which limits their usability.

The research team developed a new material whose crystal structure changes when exposed to a specific gas, and based on this, color and resistance change simultaneously.A highly selective gas sensor was fabricated.

The research team synthesized cesium kappa iodide, a non-toxic, eco-friendly copper (Cu)-based metal halide thin film material.

▲ Schematic diagram showing how the crystal structure changes due to water molecules (Image source: Korea Institute of Materials Science)

Later, supercomputer-based simulations demonstrated that the material could exhibit reversible properties and that water molecules were effective crystal change stimuli.

In addition, by designing and manufacturing a sensor element based on this theory, we confirmed that the element is excellent at detecting water molecules and successfully distinguished various alcohols with different polarities by simultaneously utilizing electrical characteristics and color changes.

Semiconductor gas sensor technology is lightweight, miniaturized, and suitable for mass production, and can be used in a variety of fields, including mobile, the Internet of Things (IoT), and agriculture and livestock industries.

This technology is of great significance in that it presents a new sensor concept and demonstration case using a crystal structure-changing material for the first time in the world.

In addition, by fabricating a sensor with gas selectivity from the material itself, excellent selectivity is achieved without additional processing.

In addition, since both color and resistance change, it can be used like litmus paper or in the form of an electronic device, so it has high versatility, and if it applies technology to improve reactivity and selectivity used in general sensors in the future, it is expected that mass production and marketability will be possible within a few years.It works.

“We should pay attention to the fact that this study suggests a new direction for the development of semiconductor sensor elements and related new materials,” said Senior Researcher Jinwoo Choi of the Materials Research Institute and Senior Researcher Hanseul Kim of the KISTI, who are the principal investigators of the study. “The sensor material developed this time has multi-response characteristics, so it is expected to be applied to various industrial fields such as agriculture, livestock, medicine, and mobile in the future.”