A research team from the School of Engineering at Princeton University in the United States has developed an ultrathin semiconductor material that can be "programmed" using light. This material, only a few molecules thick, can repeatedly alter its electronic and optical properties under different wavelengths of light, enabling programming, erasing, and reprogramming. This breakthrough could aid in the development of low-energy sensors, novel optoelectronic devices, and computing technologies. The findings were published in the latest issue of the journal Science Advances.

Researchers have developed an ultrathin semiconductor that can repeatedly change its properties in response to light. Image credit: Princeton University website

Over the past few decades, the semiconductor industry has primarily improved computing performance and energy efficiency by continuously shrinking device dimensions. However, as chip feature sizes approach physical limits, further miniaturization of semiconductor devices faces increasing challenges. The team therefore began exploring new semiconductor materials with dynamically tunable properties, aiming to advance electronic technology by starting with the materials themselves.

Currently, traditional semiconductors widely used in electronic devices such as televisions and computers are primarily controlled via electrical signals. Once a material is manufactured, its conductive properties typically do not undergo significant changes. In contrast, the semiconductor material developed in this study can actively respond to external stimuli and alter its own properties as needed.

The team combined an ultrathin semiconductor material with light-responsive molecules. These molecules undergo structural changes when exposed to different wavelengths of light, which in turn modify the electronic properties within the semiconductor, allowing the material's conductivity and optical response to be tuned via light signals. Unlike traditional semiconductors, whose performance is largely fixed after manufacturing, this new material can dynamically adjust its state based on light conditions and can be programmed and erased multiple times. This modulation is not a simple "on-off" switch but rather enables continuous variation. By changing the light conditions, the material's response level can be gradually adjusted and reversed as needed, endowing the material with more flexible programmable characteristics.

Currently, the team has fabricated a uniform ultrathin semiconductor material approximately one inch square and used it to construct an array of programmable electronic switches. This achievement demonstrates that the material has the potential to be scaled up to larger integrated systems.