Delaware team creates graphene-silicon devices for photonics applications

Researchers at the University of Delaware have invented a technology that is meant to improve the communication between photonics devices. This new innovation could benefit smartphones, laptops, and various other consumer electronics.

silicon-graphene devices capable of transmitting radio-frequency waves at less than a picosecond at a sub-terahertz bandwidth have been successfully created. Silicon has long been a popular material for use in semiconductors found in many electronic devices. Unfortunately, there is a limit to what silicon can do in a semiconductor, due to its carrier mobility. This means that the speed a charge moves through the material, and its indirect bandgap, can dramatically limit the material’s ability to absorb and release light. But scientists believe they’ve found a solution to this problem, in the form of graphene.

The first challenge with this work involved combining graphene and silicon. Scientists took the graphene and placed it in an interface between the materials, which is known as a p-i-n junction. This allowed researchers to optimize the structure of the material, which in turn significantly improved the speed and responsivity of the devices.

The entire process takes place on a wafer that’s just 12-inches in length, and incredibly thin. The components in the technology are also remarkably small, less than a millimeter in size. The components were easily fabricated, and could be commercialized with relative ease.

This work may have numerous applications in a variety of different fields. Silicon and graphene, when combined, could be used to create a photodetector that can create currents and detect light, while simultaneously offering more bandwidth and a distinctly lower response time than those found in current models. Researchers are currently looking for new ways to expand the applications of their new material, and investigating more components that have a similar structure.