Researchers are hoping to harness the power of tiny defects in incredibly thin materials to one day manufacture computer chips that are faster and more efficient than traditional silicon semiconductor platforms.
“All of our existing electronic devices use chips made from silicon, a three-dimensional material,” he said. Shoaib KhalidPhysicist at the Princeton Plasma Laboratory statement“A lot of companies are now investing heavily in chips made from 2D materials.”
This type of “two-dimensional” material, known as transition metal dichalcogenides (TMDs), is only a few atoms thick. Computer chips made from these ultra-thin semiconductors can pack much more processing power into a smaller surface area, enabling the development of smaller, faster devices.
According to a study published May 24 in the journal 2D MaterialsKhalid’s team investigated whether using TMDs, rather than silicon, might offer a solution to the idea that silicon-based chip innovation is reaching its peak.
The thinnest TMDs are just three atoms thick and arranged like a sandwich: the “bread” is made up of chalcogen atoms (elements from group 16 of the periodic table, such as oxygen and sulfur), and the “filling” is made up of transition metal atoms from groups 3 to 12.
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The scientists investigated whether they could exploit tiny atomic-sized imperfections, called defects, in slightly thicker TMDs.
Most of the atoms in a TMD are arranged in a neat, uniform pattern, but occasionally atoms are missing or packed in places they shouldn’t be. Despite the name, defects aren’t necessarily a bad thing, the researchers said in the study. For example, some defects can make a TMD more conductive.
To harness the positive effects of defects and reduce their negative impacts, scientists needed to understand how defects arise and how they affect materials performance. In this study, Khalid’s team identified the types of defects that are most likely to arise in TMDs and investigated how those defects affect material properties.
First, the team investigated defects in which one chalcogen atom is missing. study A TMD material called molybdenum disulfide had been shown to unexpectedly emit infrared light when illuminated with light. Khalid’s team discovered that the infrared emission is caused by the movement of electrons relative to the spaces where the missing chalcogen should be.
“Our work provides a strategy to investigate the presence of these vacancies in bulk TMDs,” Khalid said in a statement. “We explain previous experimental results shown in molybdenum disulfide and predict that they will occur in other TMDs as well.”
Next, the researchers studied a type of defect in which an extra hydrogen atom is wedged between two adjacent transition metal atoms. Occurs during the formation of TMDThe extra hydrogen atoms give some (but not all) of the TMD material a slight negative charge, turning it into an “n-type” semiconductor.
Computer chips rely on a combination of n-type and positively charged “p-type” semiconductors. Scientists already knew that some TMD materials could act as n-type semiconductors, but the new research explains where the extra negative charge comes from.
Understanding how these defects affect TMD performance could help researchers develop the next generation of computer chips, the scientists said in the study. While TMD chips aren’t ready to hit the shelves yet, Companies are researching ultra-thin TMD chips To address energy-intensive AI operations.
