Scientists have developed a new type of semiconductor material that can do something unusual: it can tell the difference between left- and right-handed light while also responding to visible light.
This breakthrough could help create more advanced technologies in areas like optical communication, sensing, and energy conversion.
The research was led by a team at University at Buffalo and published in Nature Communications.
It focuses on a special class of materials known as chiral semiconductors.
“Chiral” means that something has a handedness, like how your left and right hands are mirror images but not identical.
Many molecules in nature, including DNA, have this property.
In the same way, chiral semiconductors have structures that are either left- or right-handed.
This allows them to interact differently with light that also has a handedness, known as circularly polarized light. This ability is useful because it can add an extra layer of information to how light is used in technology.
However, there has been a major limitation. Most chiral semiconductors do not respond well to visible light. Instead, they mainly interact with higher-energy ultraviolet light.
This happens because of something called a bandgap, which is the energy needed for electrons in a material to move and carry current. In many chiral materials, the bandgap is too large for visible light to trigger this movement.
To solve this problem, the researchers combined a chiral semiconductor with a different type of molecule that is not chiral but can easily absorb visible light. The chiral material they used is based on a type of crystal called Perovskite. They then added a second molecule, called F4TCNQ, which is good at accepting electrons.
When these two materials were combined and exposed to visible light, something interesting happened. The chiral semiconductor still kept its handedness, meaning it could distinguish between left- and right-handed light.
At the same time, the added molecule helped the system absorb visible light by allowing electrons to move more easily between the two materials.
In simple terms, one material “reads” the handedness of light, while the other helps capture its energy. Together, they create a system that can do both jobs at once.
The researchers compare this teamwork to a basketball play. One player sets up the move and passes the ball, while the other completes the action. In this case, the chiral material passes information about light’s handedness to the second molecule, which helps process it.
This discovery opens the door to new kinds of optoelectronic devices, such as sensors that can detect subtle differences in light, faster communication systems, and improved materials for chemical reactions driven by light.
The team now wants to better understand how this transfer of “handedness” happens at the electron level. By learning more about this process, scientists hope to design even more efficient materials in the future.
Overall, this research brings us closer to building smarter, more responsive technologies that use light in more powerful and precise ways.
