What are Quantum Dots (QD)?
Quantum dots are light-emitting semiconductor nanocrystals with the ability to absorb high energy light of one wavelength and efficiently convert it to low energy light of other specific wavelengths to create more distinct reds, greens and blues on LCD displays.
The wavelength of the light – or the colour – that quantum dots emit is dependent on the particle size. The smallest quantum dot emits blue light and the largest emits red. The peak emissions of quantum dots can be tuned to within 1 nm giving excellent control over the colour spectrum output of displays.
The colour produced by quantum dots (QD) is dependent on the size of the particle ranging from 2nm to 6nm. Typically, a 2nm QD emits blue light, a 3nm QD emits green light, a 6nm QD emits red light.
Quantum dot technology has been very popular since 2014 for LCD displays as the colours they emit are extremely pure with excellent colour contrast. The ability to produce highly tuned peaks and purer spectral emission enables it to achieve a wider range of colours that are clearer, more accurate and truer to life for the viewer. By expanding the colour gamut of displays, quantum dots make it possible for LCD displays to meet the colour performance of OLED displays, while maintaining the cost structure of LCD displays.
Unfortunately, conventional quantum dots are typically cadmium-based (CdSe) or made of metal chalcogenide, materials that according to the Restriction of Hazardous Substances (RoHS) Directive may be unsafe for the environment and a threat to human health.
Perovskite Nanocrystals for Displays
Perovskite nanocrystals are a new class of halide semiconductor nanocrystals that possess all the advantages of quantum dots and more.