Quantum dots (QDs) are semiconductor nanocrystals which can produce pure monochromatic red, green, and blue light. Their optoelectronic properties change as a function of both size and shape although the specific colors vary depending on the exact compostion of the QD. Larger QDs of 5-6 nm diameter emit longer wavelenghts, with colors such as orange or red. Smaller QDs of 2-3 nm diameter emit shorter wavelenghts, yielding colors like blue and green.
QD displays use blue LEDs as the light source. When the blue light passes through the QD film, the light is converted into exact colors of RGB. Therefore, QD displays are capable of reproducing natural colors, showing higher color gamut than OLEDs.