Princeton group creates light-configurable 2D-based device
Researchers at Princeton Engineering have combined monolayer of WS2 and WSe2 with an overlay of light-responsive azobenzene (Azo) molecules, to created a device that repeatedly changes its properties in response to light.
Their paper, 'Large-area, photo-programmable 2D semiconductors with chromic molecular functionalization', was published July 1 in Science Advances.
The Azo molecules change structure when exposed to different wavelengths. These changes alter the semiconductor’s electronic properties, allowing its conductivity and optical response to be programmed, erased, and reprogrammed with light.
This means that the material does not function like a simple on-off switch. “Instead of switching directly from zero to one, we can gradually adjust the material’s response and then reverse the process,” said Jaehoon Ji, post-doctoral researcher and first author on the paper.
The researchers have created a uniform piece of the semiconductor that is 1-inch square. Using this, they have built arrays of programmable electronic switches, a step toward larger integrated systems. Next, they are working to connect these switches into a circuit, a fundamental building block for any complex electronic device.
The researchers believe this is a step toward building more energy-efficient sensors, optoelectronic devices and computing technologies. “One of the future goals for advancing electronics is not just making materials smaller, but making them adaptable and smarter,” said Jaehoon Ji, post-doctoral researcher and first author on the paper describing the research in Science Advances.
“Our long-term vision is to build electronics whose functionality is no longer fixed during fabrication,” said Saien Xie, assistant professor of electrical and computer engineering and the paper’s lead author. “Instead, we want devices whose properties can be dynamically reconfigured after they are made. This work demonstrates an important step toward that goal.”
