OLED (Organic Light Emitting Diodes) TVs use organic materials that emit light when they are applied electricity, but they do not need backlight. These televisions are thus brighter but at the same time more efficient, thinner and feature better refresh rates and contrast. The first company to develop this kind of technology was LG, but now we can find these televisions in order companies, like Samsung.
OLED materials were discovered back in 1960, but only in the past 20 years or so have researchers started to actually work on the technology. Now, OLED technology is very related to 4K definition and more cool stuff, like flexible, rollable and transparent TVs. LG is developing a 4K rollable TV. This will indeed give TV designers a freedom of design and totally redefine the TV of the future.