Super efficient 2D semiconductor devices

Super efficient 2D semiconductor devices

Smartphones, laptops and smartwatches consume vast quantities of energy, yet only around half of this energy is actually used to power important functions. And with billions of these devices in use worldwide, a significant amount of energy goes to waste.

Professor Adrian Ionescu and his team at EPFL’s Nanoelectronic Devices Laboratory (Nanolab) have launched a series of research projects in the quest to make transistors more energy-efficient. “The transistor is the most abundant artificial object ever created by humans,” says Prof. Ionescu. “It enables our entire computational infrastructure and the way we interact in real time with portable information processing in the 21st century. It forms the basic building block for both digital and analog signal processing.”

Energy efficiency matters

“Today, we know that the human brain consumes about the same quantity of energy as a 20 Watt bulb,” says Ionescu. “Despite consuming so little energy, our brain is capable of performing tasks that are several orders of magnitude more complex than what a computer can handle – analyzing information provided by our senses and generating intelligent decision-making processes. Our goal is to design electronic technology for portable devices that’s similar in efficiency to human neurons.” The transistor built by the EPFL researchers raises the bar for energy efficiency. Developed in the School of Engineering (STI) clean room, it comprises 2D layers of tungsten diselenide (WSe2) and tin diselenide (SnSe2), two semiconducting materials. Known as a 2D/2D tunneling transistor, it exploits the band alignment of the WSe2/SnSe2 gate junction. And because it measures just a few nanometers, it is invisible to the human eye. As part of the same research project, the Nanolab team also designed a new hybrid dual-transport structure that could one day push technology performance even further.