Most of the screens we use are of two types: LCD and OLED. LCD, or liquid crystal displays, as the name suggests, are composed of liquid crystals. Under the action of a voltage that is applied between the upper and lower electrodes, the transparency of the crystals changes, small pixels are formed. These pixels are painted in different colors using a special light filter - this is how you get a finished color picture.
OLED screens glow by themselves. Oleds, or organic LEDs, are amazing molecules that produce light when energized. On the one hand, we inject the so-called holes, and on the other, electrons that meet, enter the organic semiconductor and initiate the process of light emission.
LCD screens are in many ways inferior to the "ice" ones. For example, blacks on LCD screens always remain a little grayish due to background lighting. In addition to more accurate color reproduction, OLED screens are sharper and consume less power.
For the production of both OLED and liquid crystal panels, the same chemical element is used - indium, or rather indium tin oxide. The thickness of its layer is half a micron, that is, ¼ of a human hair. It is transparent, invisible to the eye, but conducts current, at the same time, no worse than any metal.
As the consumption of electronics grows, so does the demand for the material itself. If in 2002 a kilogram of indium cost about $ 100, then already in 2006 - from 400 to 900 dollars. There is not much of it left in the earth's crust, resources may at some point be exhausted, which means that manufacturers have to think about alternatives.
A probable replacement for the indium tin oxide used in OLED screens is single-wall carbon nanotubes or nanorods made of various metals, in particular, silver. Their notable advantage is the ability to manufacture flexible and even stretchable surfaces. Several manufacturers have recently unveiled prototypes of bendable smartphones, and LG, for example, has developed a prototype TV that literally rolls into a roll. The use of such devices is not yet obvious. But they have great potential for a completely new generation of technology: Google and Levi's are already releasing a limited collection of Jacquard smart clothes. The research team used nanorods to replicate the ancient technique of making jacquard fabric so that the display is always at hand, literally.
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All of these new products are coming to retail, but that doesn't mean flexible nanotube or nanorod screens will replace indium tin oxide tomorrow. After all, you rarely want a computer monitor that folds in half. Any long-term forecasts should be treated with caution, nevertheless, the state of the modern technological ecosystem suggests that over the next twenty years flexible screens will create a separate niche, and OLED screens powered by indium tin oxide will somehow remain the basis of mass production.
Dmitry Godovsky