New erasable chip uses light to rewrite how electronics behave after fabrication

Researchers at Princeton University developed a thin semiconductor that can be programmed, erased and reprogrammed using different wavelengths of light. Unlike conventional semiconductors, whose electrical properties are largely fixed once fabrication is complete, the new material can be adjusted repeatedly. The team combined a two-dimensional semiconductor with light-responsive molecules. When exposed to specific wavelengths, the molecules change their structure. That change alters the semiconductor’s electronic and optical properties, allowing its response to be controlled without rebuilding the material. The researchers say this could eventually lead to electronics whose functions can be changed after manufacturing rather than being permanently determined during fabrication. Light gives semiconductors new control “The first step to creating smart materials is responsiveness,” said Saien Xie, assistant professor of electrical and computer engineering and the paper’s lead author. “Living systems are extremely smart, because they continuously sense and respond to their surroundings. We wanted to create a material that can similarly respond to external stimuli instead of remaining permanently fixed.” The material also moves beyond the binary behavior associated with conventional electronic switches. Instead of simply representing an on or off state, its response can be gradually adjusted and then reversed using light. “Instead of switching directly from zero to one, we can gradually adjust the material’s response and then reverse the process,” Ji said. This capability comes from the interaction between the semiconductor and the molecules attached to it. Changing the molecules’ structure changes how the semiconductor conducts electricity and responds to light, giving researchers a way to tune its properties dynamically. The work could be particularly useful for programmable electronics, where changing a device’s behavior normally requires different hardware or circuitry. One-inch material points toward circuits The team has already produced a uniform piece of the semiconductor measuring 1 inch square. Using the material, researchers built arrays of programmable electronic switches, demonstrating that the light-controlled behavior can be incorporated into functional structures rather than remaining limited to small laboratory samples. The next step is to connect these switches into a circuit. Circuits are the basic building blocks used to create more complex electronic systems, so demonstrating a working circuit would move the technology closer to practical devices. The researchers envision electronics that could be modified after they leave the manufacturing process. That could allow the same hardware to take on different functions without requiring a new semiconductor design for every application. “Our long-term vision is to build electronics whose functionality is no longer fixed during fabrication,” Xie said. “Instead, we want devices whose properties can be dynamically reconfigured after they are made. This work demonstrates an important step toward that goal.” The approach is still at an early research stage. The current demonstration shows programmable semiconductor switches, while larger integrated circuits and complete electronic devices remain future targets. If the technology can be scaled, light could provide a new way to control semiconductor properties without physically modifying the underlying material. That could open a path toward electronics that are more adaptable than today’s fixed-function chips.The study, “Large-area, photo-programmable 2D semiconductors with chromic molecular functionalization,” was published in Science Advances.Get the latest in engineering, tech, space & science - delivered daily to your inbox.With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn’t chasing stories, she’s likely lost in a book or enjoying the company of her dogs.