New Ultra thin Conductor Promises More Efficient, Cooler Electronics
Stanford researchers have revealed a new ultrathin conductor that should prove a boon to nanoelectronics by enhancing energy efficiency and performance. The material, niobium phosphide, is expected to take the upper hand over copper in films a few atoms thick, ultimately paving the way for potentially cooler and more energized electronics.
Conventional metals, like copper, are limited in nanoscale electronics. Lowering the film thickness increases metals’ electrical resistivity due to enhanced electron-surface scattering, limiting performance. The new material developed by Stanford researchers would offer a promising alternative to those limitations.
Asir Intisar Khan, the study’s first author and a visiting postdoctoral scholar at Stanford, explained, “We are breaking a fundamental bottleneck of traditional materials like copper. Our niobium phosphide conductors show that sending faster, more efficient signals through ultrathin wires is possible. This could improve the energy efficiency of future chips, and even small gains add up when many chips are used, such as in the massive data centers that store and process information today.”
Niobium phosphide, or NP, is a topological semimetal, a class of materials that conducts electricity through their entire structure and are more conductive on the surfaces than in the interior.
The surfaces remain intact after the material becomes thinner, which allows conductivity to increase in general. On the other hand, metals such as copper have decreased conductivity below 50 nm thickness.
It was then discovered that niobium phosphide exceeded copper conductivity for the films thinner than 5 nm, even at room temperature. At such scales, copper wires struggle with fast electrical signals and waste energy as heat.
Eric Pop, a senior author on the paper and a professor at Stanford, explained, “High-density electronics need very thin metal connections, and if these metals don’t conduct well, they waste energy. Better materials could help reduce energy loss and improve performance.”
One key advantage of niobium phosphide is that it doesn’t require single-crystal films, a typical challenge for traditional topological materials. Instead, the films can be created at lower temperatures—just 400 degrees Celsius—making them compatible with existing silicon-based computer chip manufacturing processes.
Yuri Suzuki, a co-author of the study, emphasized the significance of this finding, stating, “Making perfect crystalline wires won’t work for nanoelectronics, but if we can make them slightly disordered and still achieve the needed properties, it could lead to practical applications.”
While niobium phosphide films show great promise, Pop and his team don’t foresee them replacing copper in all computer chips, as copper is still superior for thicker wires and films. However, niobium phosphide could prove invaluable for ultra-thin connections, which are increasingly crucial in the growing field of nanoelectronics.
The researchers are already exploring other topological semimetals that could further improve niobium phosphide’s performance.
Xiangjin Wu, another co-author and doctoral student at Stanford, remarked, “For these materials to be used in future electronics, we need them to conduct even better. We’re exploring other topological semimetals to achieve that.”
This groundbreaking discovery could open new possibilities for more energy-efficient, high-performance electronics in the coming years.
Journal Reference
- Khan, A. I., Ramdas, A., Lindgren, E., Kim, M., Won, B., Wu, X., Saraswat, K., Chen, T., Suzuki, Y., Oh, K., & Pop, E. (2025). Surface conduction and reduced electrical resistivity in ultrathin noncrystalline NbP semimetal. Science. DOI:10.1126/science.adq7096
