new technology

Scientists at the University of Tsukuba in Japan have developed a method to synthesize conjugated polymers in a helical configuration. Using twisted liquid crystals as a starting point, they obtained polymers that could convert linearly polarized light into circularly polarized light.

How does it work

These conjugated carbon-based polymers conduct electricity and have a color that can be changed by chemical doping with other molecules. Oxidation states can be quickly altered by electrical voltage, which affects chromaticity. However, further progress in the OLED field requires the emergence of new materials with new properties such as circular polarization.

Scientists have presented a method for forming polymers with spiral configurations based on back liquid crystal.

Polymers with both optical activity and luminescence function can emit polarized light in a circle. To do this, first the liquid crystal molecules are in direct configuration. The addition of monomer molecules causes the liquid crystals to twist into a spiral. This gives the structure the characteristic of chirality, orienting it clockwise or counterclockwise,
– Professor Hiromasa Goto explained.

After the electric current is supplied, the polymerization process of the monomers is started. The liquid crystal template is removed and the polymer solidifies like a spiral. It gains the ability to transform polarized light into a circle by breaking the mirror symmetry. The circles in the polymer not only promote electrical conductivity, but also help stabilize the spiral structure.

Tests of the resulting polymer showed its high optical activity at visible wavelengths. Further use of this technology could lead to cheaper and more energy efficient electronic displays.