MIT engineers fabricated 2D materials that could lead to next-generation transistors and electronic films.
True to Moore's Law, the number of transistors on a microchip has doubled every year since the 1960s. But this trajectory is predicted to soon plateau because silicon — the backbone of modern transistors — loses its electrical properties once devices made from this material dip below a certain size. Enter 2D materials — delicate, two-dimensional sheets of perfect crystals that are as thin as a single atom. At the scale of nanometers, 2D materials can conduct electrons far more efficiently than silicon. The search for next-generation transistor materials therefore has focused on 2D materials as potential successors to silicon. But before the electronics industry can transition to 2D materials, scientists have to first find a way to engineer the materials on industry-standard silicon wafers while preserving their perfect crystalline form. And MIT engineers may now have a solution. The team has developed a method that could enable chip manufacturers to fabricate ever-smaller transistors from 2D materials by growing them on existing wafers of silicon and other materials. The new method is a form of "nonepitaxial, single-crystalline growth," which the team used for the first time to grow pure, defect-free 2D materials onto industrial silicon wafers. With their method, the team fabricated a simple functional transistor from a type of 2D materials called transition-metal dichalcogenides, or TMDs, which are known to conduct electricity better than silicon at nanometer scales. "We expect our technology could enable the development of 2D semiconductor-based, high-performance, next-generation electronic devices," says Jeehwan Kim, associate professor of mechanical engineering at MIT. "We've unlocked a way to catch up to Moore's Law using 2D materials." Kim and his colleagues detail their method in a paper appearing today in Nature. The study's MIT co-authors include Ki Seok Kim, Doyoon Lee, Celesta Chang, Seunghwan Seo, Hyunseok Kim, Jiho Shin, Sangho Lee, Jun Min Suh,…