The heading materials were prepared by Denis BOROVITSKY, Alexey VOROBYEV-OBUKHOV
LED OR LIQUID CRYSTAL?
So far, there has been a clear distinction: when voltage is applied, the LED shines, the liquid crystal darkens. Now, however, the edges are erased …
The new OLED (Organic Light Emitting Diode) soon promises to replace existing displays. Anyone who held a traditional LED in their hands knows: this is a small crystal hidden in a drop of plastic, or a steel case with a glass window. We connect the leads to the battery and enjoy a more or less bright light, usually red, yellow or green. At first glance, OLED includes the thinnest film that glows over the entire surface. In fact, this is a complex multilayer structure.
Everything should be based on a base, such as glass. Then - the anode: a layer of indium and tin oxide, thin until transparent. A “plus” from the battery is subsequently connected to it. On the anode, we drip the liquid “Baytron R” (Baytron P) as dark as ink. When it spreads over the surface, there will be no trace of blackness. It is this composition that represents the organic molecular structure patented by Bayer, Agfa, Bosch and the University of Bayreuth (Germany). It is this film that glows brightly later, when the LED is assembled.
For those who are interested in the intricacies of the design of the new LED, let's say that the light-emitting part itself consists of three layers: an electrically conductive Bytron, phenylamine, and the actual light-emitting coating.
Finally, close the entire structure with an opaque cathode of calcium or magnesium - and connect the current source. Between the layers, an ordered counter motion of electrons and so-called holes begins (places of the lattice where there is no electron). Faced with each other in the thinnest (about 0.01 mm) OLED layer, they “explode” (in a scientific way, recombine), and these flashes merge into an even bright and beautiful light.
New LEDs are characterized by insignificant energy consumption, high light output and, most importantly, they can be bent, twisted, made of any shape. So for the imagination of designers of virtual instrument combinations, displays of on-board computers and navigators that do not need additional illumination, full scope opens up.
Dr. A. Elshner presents a novelty.