Light is generated with the help of exotic “exciton clusters” in layers of just a few atoms thickness. When particles bond in free space, they normally create atoms or molecules. However, much more exotic bonding states can be produced inside solid objects. Now this has been utilized at the Vienna University of Technology. So-called “multi-particle exciton clusters” have been produced by applying electrical pulses to extremely thin layers of material made from tungsten and selenium or sulphur. These exciton clusters are bonding states made up of electrons and “holes” in the material and can be converted into light. The result is an innovative form of light-emitting diode in which the wavelength of the desired light can be controlled with high precision. These findings have now been published in the scientific journal “Nature Communications”.
“Our luminous layer system not only represents a great opportunity to study excitons, but is also an innovative source of light”, says Matthias Paur, lead author of the study. “As a result, we now have a light-emitting diode whose wavelength can be specifically influenced – in fact very easily, simply by changing the shape of the electrical pulse applied.”