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Researchers from Cambridge and the Eindhoven University of Technology have developed an organic semiconductor, that can make OLED monitors and smartphone screens many times brighter.
It is noted that this semiconductor with triazatruxene, causes electrons to move in a spiral, which can significantly increase the brightness of OLED screens and their energy efficiency. This semiconductor is based on the principle of chirality — the interaction of similar structures that mirror each other.
The majority inorganic semiconductors, for example, silicon-based systems use the principle of symmetry. However, the new chiral semiconductor directs electrons in a spiral motion and emits light in the direction of clockwise.
When the spiraling electrons are excited by blue or ultraviolet light, they begin to emit a bright green light with a strong circular polarization. This property has long been very difficult to achieve in semiconductors.
«The TAT structure allows electrons to move efficiently, affecting how light is emitted. This is a real breakthrough in the creation of a chiral semiconductor. By carefully designing the molecular structure, we have linked the chirality of the structure to the movement of electrons, and this has never been done at this level», — said one of the study’s lead authors from the Eindhoven University of Technology Marko Prois.
The study builds on decades of collaboration between the research teams of Professor Sir Richard Friend of Cambridge and Professor Bert Meyer of Eindhoven. Creating a similar semiconductor allows us to achieve a breakthrough in color reproduction technology in modern OLED TV displays and smartphone screens. Currently, these devices consume a significant amount of energy as they use filters to control the light emitted. The new chiral semiconductor naturally emits polarized light, so you won’t need these filters, and your screens will be brighter and more energy efficient.
In one experiment, TAT was embedded in circular polarized OLEDs (CP-OLEDs). These devices achieved record levels of efficiency, brightness, and polarization.
«We essentially reworked the standard recipe for OLED manufacturing, as in our smartphones, which allowed us to encapsulate the chiral structure in a stable, non-crystallizing matrix This provides a practical way to create circularly polarized LEDs, which has eluded the industry for a long time», — says Rituparno Chowdhury, one of the lead authors from the Cambridge Cavendish Laboratory.
However, the development will not be limited to the use of OLED displays in electronic devices. The ability to control the spin and motion of electrons opens up new possibilities for quantum computing and spintronics — fields that seek to harness the inherent angular momentum of electrons to store and process information. For a long time, organic semiconductors were considered inefficient. However, they are now one of the key elements of the industry, whose financial volume has already reached $60 billion a year.
«When I started working with organic semiconductors, many people doubted their potential, but now they dominate display technology Unlike rigid inorganic semiconductors, molecular materials offer incredible flexibility, allowing us to design entirely new structures such as chiral LEDs. It’s like working with a Lego set that has all the shapes you can imagine, not just rectangular bricks», — explains Cambridge team leader Professor Sir Richard Friend.
The results of the study were published in the journal Science
Source: ZMEScience