A colour revolution (Image: Sony)

Your next TV might be a quantum one. Sort of. Light-emitting nanoparticles called quantum dots are finally coming out of the lab and into our living rooms, bringing better colour to LCD flat-panel screens. The first TVs with the new technology, Sony’s Triluminos sets, reached stores this month.

Reds are “rich, vibrant and vivid, green grass looks like grass, and scenes of the Caribbean are stunning”, says Seth Coe-Sullivan, founder and chief technology officer of the company behind the quantum dots, QD Vision based in Lexington, Massachusetts. A reviewer for TechRadar website agreed, writing: “colours enjoyed both a wider, richer tonal range and more subtlety in their blends than LCD TVs normally deliver.”

Quantum dots are tiny bits of semiconductor that are able to tightly confine electric charge and emit light. When illuminated, they produce colours that are exceptionally pure. So while the dots only create colours that span 10 per cent of the visible spectrum, they can be mixed to show nearly all of the colours the human eye can see, says Coe-Sullivan. In contrast, mixing the less-pure red, green and blue emissions in standard LCD displays gives only about two-thirds of the colour range visible to the eye.


Size matters

The trick to making the colours pure is to make all the quantum dots as close in size as possible. This narrows the wavelength at which they emit light. A big part of QD Vision’s success has been controlling the size of quantum dots to within 0.1 nanometre.

In televisions, QD Vision embeds quantum dots in a thin plastic rod that sits at the edge of the screen. Blue LEDs excite red and green emission from the dots, and a sheet of plastic 3 to 4 millimetres thick spreads the combined light, which looks white to the eye, across the back of the LCD screen. The LCD screen has an array of shutters with different-coloured filters, which change to create the different colours that we see. They take the place of an array of white LEDs used in most current displays.

Competition is close on their heels. This week 3M and Nanosys of Palo Alto, California, showed samples of a quantum-dot film designed to sit between an array of blue LEDs and an LCD. The film can “deliver richly saturated colours, while minimising power consumption”, says Ty Silberhorn of 3M. They will start delivering samples to display makers next month.