Scientists in Korea have succeeded in developing two-dimensional semiconductors with a performance much higher than that of conventional models. This could take a big leap forward in artificial intelligence technologies and systems.
They are tiny and at the same time extremely important: semiconductors can be found in many famous objects such as light emitting diodes such as OLEDs, solar cells, vehicles, coffee machines and smartphones. They are integrated into microchips built into the control units that regulate driving and braking behavior in cars, as well as airbags and assistance systems. They are also used in autonomous driving. In this case, the systems even have to act like the human brain and logically process large amounts of data.
Sensors and semiconductors are still in demand
Most of the existing semiconductors are made of silicon. There are also those based on other chemicals such as boron, selenium and tellurium. Although silicon-based semiconductors are very common, they have the disadvantage of being relatively expensive to process and consuming a certain amount of energy. Therefore, scientists are working intensively on alternatives. The focus of research is on very thin, two-dimensional semiconductors based on the atomic layer levels. Another challenge for them is that their electrical properties cannot be controlled as easily as with semiconductors made of silicon. For this reason, it has hitherto been technically difficult to implement various so-called logic devices with two-dimensional semiconductors. The research team in Korea did just that.
2D semiconductors can be selectively driven
A group at the Korea Institute of Science and Technology (KIST) led by Do Kyung Hwang of the Optoelectronic Materials and Devices Center and Kimoon Lee of the Kunsan National University Department of Physics implemented two-dimensional semiconductor electronics and device logic. Their properties can be completely freely controlled remotely thanks to the new ultra-thin electrode material. This was achieved by using the so-called CI-doped tin selenide (CI-SnSe2). This two-dimensional electrode material allowed for selective control of electronic semiconductor elements in experiments carried out by scientists.
Until now, circuits using traditional two-dimensional semiconductor devices have exhibited the characteristics of N-type or P-type devices, but not both. These semiconductors have a so-called positive P region on one side and a negative N region on the other side. Now that the research team has minimized the defects at the semiconductor interface, one semiconductor now performs the functions of N-type and P-type devices. This reduces the effort involved in manufacturing. For example, in solar cells there are also p-type n cells. The different electric charges are caused by the use of chemicals: In addition to silicon, a p-cell mainly contains boron, which has one electron less than silicon, and therefore the cell is positively charged. In the case of an n-type cell, in addition to silicon, mainly phosphorus is used. It has one more electron than silicon and therefore the cell is negatively charged. P-type cells are believed to be more resistant, which is why they have long been the most frequently used cells in solar systems. In the meantime, however, manufacturers also rely on n-cells as they are much more efficient. Moreover, they show no loss of performance due to initial exposure to light, the so-called light induced degradation (LID).
2D semiconductors: overcoming the obstacles to miniaturization
At the same time, this high performance complementary logic circuit has a low power consumption. Scientists are confident that they have made a major contribution to accelerating the next steps in AI systems. Because they would overcome the technical obstacles caused by miniaturization. Since the material they developed is very thin, it also has high light transmission and flexibility. This is what makes it so attractive for future semiconductor components.
The Korean Institute of Science and Technology (KIST) was founded in Korea in 1966 as a state-funded research institute. Research on semiconductors was supported by a special program: Nanomaterials Technology Development Project and Information and Communication Technologies Development Project financed by the Ministry of Science.
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