Quantum dots boost colour, save energy

Quantum dots is heralding a new generation of displays that boast a much better range of colour reproduction along with reduced energy consumption. American nanomaterials company QD Vision is behind the technology that will harness this using its Color IQ system. Two manufacturers, Sony and TCL, have already started using Color IQ in their screens that are only available in the buoyant Chinese display market, for now. Within months these displays will be rolled out worldwide.

Quantum dots are light-emitting semiconductor nanocrystals that can be tuned to emit all colours across the visible spectrum by changing their size, nanometer by nanometer. By tuning these dots to red and green, and using a blue backlight to energise them, QD Vision has developed an optical component that can boost the colour gamut for LCD displays by around 50%, with energy-efficiency being increased by roughly 20%.

In LCD screens pixels are illuminated by a white LED backlight that passes through blue, red, and green filters to produce the colours on the screen. Because this process requires phosphors to convert a blue light to white efficiency is lost and the colour gamut is affected. Boosting colour by incorporating more LEDs would lead to greater cost and energy usage.

QD Vision’s Color IQ is a thin glass tube, filled with quantum dots tuned to red and green. Manufacturers use a blue LED in the backlight, but without the need for conversion phosphors. As blue light passes through the Color IQ tube, some light shines through as pure blue light, while some is absorbed and re-emitted by the dots as pure red and pure green. With more light shining through the pixels, QD Visions says LCD diplays equipped with Color IQ produce 100% of the colour gamut, with greater power efficiency.