Breakthrough research has shown that twisting light into spiral patterns like those found in nature dramatically improved the efficiency of OLED screens.
The researchers behind the novel approach believe their method for twisting light could revolutionize the efficiency of electronics, including display technologies like OLEDs and night vision.
In the nearly 150 years since the invention of the light bulb, the science of light has continued to advance. As the use of electronic devices involving display technologies has rapidly spread in recent decades, scientists have been searching for new and innovative ways to control the chaotic behavior of light or even manipulate light at the sub-wavelength scale to improve the performance and efficiency of those devices.
Twisting Light: Just the Latest Breakthrough in Light Manipulation
In 2023, City College of New York (CCNY) researchers successfully trapped light using magnets and metamaterials. Last year, researchers from the Netherlands were able to stop light in its tracks using a photonic crystal. Just last week, The Debrief reported on an international effort that turned laser light into a new state of matter called a super solid. The DOE has even funded experiments designed to squeeze infrared light by 90%, resulting in an entirely new optical material.
One more speculative approach covered by The Debrief involved using light to achieve a form of mind control. Still, the ultimate goal for many of these efforts is the improvement of electronic devices that utilize light. Some of those approaches involve using metamaterials for light transmission, harnessing hurricanes of light to improve efficiency, or even tapping into Thomas Edison’s original designs to generate twisted light.
The latest effort, led by researchers from the University of Cambridge and the Eindhoven University of Technology, successfully twisted light in an OLED display, heralding a potential breakthrough in light manipulation.
Creating Chirality to Imitate Nature
According to a statement from the research team, molecules often have a chiral structure, meaning they are left—or right-oriented, similar to human hands. However, replicating this natural state in electronics to take advantage of the design’s inherent efficiencies has proven challenging.
In their published study, the team approached the problem by developing a customized chiral semiconductor by “nudging” stacks of semiconducting molecules to form left and right-handed columns that operated by twisting light into a forced chirality.
The customized semiconductor is based on triazatruxene (TAT), a material that “self-assembles” into helical stacks. According to the study’s co-first author, Marco Preuss, from the Eindhoven University of Technology, this unique structure allows electrons traveling along its structure to spiral similarly to the threads on a screw.
twisting light
Confocal microscopy images: Taken by Samarpita Sen, The Gurdon Institute, University of Cambridge. Rendered in this form by Rituparno Chowdhury. Credit: Samarpita Sen/Rituparno Chowdhury.
“When excited by blue or ultraviolet light, self-assembled TAT emits bright green light with strong circular polarisation—an effect that has been difficult to achieve in semiconductors until now,” said co-first author Marco Preuss, from the Eindhoven University of Technology. “The structure of TAT allows electrons to move efficiently while affecting how light is emitted.”
In this case, the semiconductor material emitted circularly polarized light. This means that the light carried “information” about whether the electrons are left-handed or right-handed. The team says this design is markedly different from inorganic semiconductors like those made from silicon, whose symmetrical internal structure allows electrons to move through them “without any preferred direction.”
Modified OLED Shows Dramatic Improvement in Efficiency
The team tested their new twisting light approach by modifying existing OLED fabrication techniques, so TAT was directly incorporated into working circularly polarized OLEDs (CP-OLEDs). The result was devices that “showed record-breaking efficiency, brightness, and polarisation levels.”
“We’ve essentially reworked the standard recipe for making OLEDs like we have in our smartphones, allowing us to trap a chiral structure within a stable, non-crystallising matrix,” said co-first author Rituparno Chowdhury from Cambridge’s Cavendish Laboratory. “This provides a practical way to create circularly polarised LEDs, something that has long eluded the field.”
Professor Bert Meijer from the Eindhoven University of Technology agreed, noting that the team’s organic semiconductor capable of twisting light could dramatically improve the efficiency of display technologies like TVs, smartphones, and night vision. The chiral semiconductors could also be critical in powering quantum computers and spintronics-based devices.
summer solstice
“This is a real breakthrough in making a chiral semiconductor,” said Meijer. “By carefully designing the molecular structure, we’ve coupled the chirality of the structure to the motion of the electrons, and that’s never been done at this level before.”
Potential to Dominate an Industry
In the study’s conclusion, Professor Sir Richard Friend from Cambridge’s Cavendish Laboratory, who co-led the research, said using organic semiconductors was once out of fashion. However, due to their myriad uses and applications, they now “dominate the industry,” supporting an industry worth over $60 billion.
“Unlike rigid inorganic semiconductors, molecular materials offer incredible flexibility—allowing us to design entirely new structures, like chiral LEDs.” Friend explained. “It’s like working with a Lego set with every kind of shape you can imagine, rather than just rectangular bricks.”
Alongside improved efficiency for electronic displays, the team believes its organic semiconductors capable of twisting light could have significant implications for quantum computing. They also see opportunities in spintronics, “a field of research that uses the spin, or inherent angular momentum, of electrons to store and process information,” which could lead to faster and more secure computing systems.
The study “Circularly polarized electroluminescence from chiral supramolecular semiconductor thin films” was published in Science.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him onX,learn about his books atplainfiction.com, or email him directly atchristopher@thedebrief.org.