Atom-thin silicon-germanium sheets for integrated photonics
The NSF has funded a project developing new materials to enable the transmission of data on chips by light instead of electricity, which could help reduce energy consumption and waste heat in datacentres
Engineers from Iowa State University have won a three-year, $552,000 grant from the National Science Foundation (NSF) to develop new materials that can allow the transmission of data on chips through light instead of electricity. The research could lead to datacentres that consume less power and generate less waste heat.
Energy consumption is spiking in the US, and datacentres could use up to 9 percent of US electricity generation by 2030 – more than double current consumption, according to a study released in May by EPRI, an independent, non-profit energy research and development organisation.
The study says the move to artificial intelligence (AI) tools is one reason for the spike. AI searches require about 10 times more electricity than a traditional internet search, while AI-generated photos, videos, and music require even more power.
Matthew Panthani, an associate professor of chemical and biological engineering at Iowa State University, believes that integrated photonics could be the solution. “Let’s use light to transmit data on chips instead of electricity,” he says. “Fibre optics has already solved this on a global scale. It’s the same concept of moving data with light. It’s efficient and fast. But it hasn’t happened with chips yet.”
This isn’t a new idea, but it has been a challenging one to realise. According to Panthani, this is because the material of choice for semiconductors is silicon, which doesn’t emit light.
To address this issue, Panthani’s lab has been working on new materials for PICs since 2017. The lab’s current focus is to develop atom-thin sheets of a silicon-germanium alloy. Those sheets can be stacked in layers separated by alkali metal ions such as lithium or salts, creating layered semiconductors.
The new NSF funding will support Panthani’s latest work to develop the semiconductors. Three doctoral students – Andrew Tan, Abhishek Chaudhari and Maharram Jabrayilov – will contribute to the effort. The grant will also bring high-school teachers into the lab during the summer months, helping them improve their teaching by learning more about scientific research.
In addition to synthesising the semiconductors “with precise control over the arrangement of atoms in the material,” a project summary says the researchers will study how structure and chemistry influences the semiconductors’ optical and electronic properties and they’ll determine their thermal and environmental stability. All of that would advance basic knowledge in materials chemistry, nanotechnology and semiconductors.
Basically, Panthani says, the semiconductors would emit light “and we want to understand how they could emit light better.” Achieving that could have real-world applications and implications. According to the project summary: “Integrated photonic circuits have the potential to result in computers and mobile phones that use much less electricity and operate faster.”
Image credit: Photo by Christopher Gannon/Iowa State University
