Sony is using nanoscale particles called quantum dots to significantly improve the color of some of its high-end Bravia televisions. It showed off the technology, which increases the range of colors that an LCD television can display by about 50 percent, at the Consumer Electronics Show in Las Vegas this week. This marks the first time that quantum dots—which for a long time have fascinated researchers because of their unusual electronic and optical properties—have been used in a mass-produced consumer electronics product.
Quantum dots emit very specific wavelengths of light. And the precise colors they emit can be tuned by changing their size. Sony is incorporating technology from QD Vision, which has been working to commercialize advances made at MIT over a decade ago. Originally, the company aimed to make quantum dot displays that are similar to OLED displays—the quantum dots would form the pixels of the display, and would be turned on and off by applying electrical current via a transistor. Although QD Vision has developed prototypes of these displays, they’ve been difficult to make reliably in large sizes (see “This Display Is a Quantum Leap”).
The product that’s finally coming to market is far different. Sony’s new television is a modified LCD TV. In LCD televisions, each pixel is illuminated from behind by a white backlight, and different colors are created by changing the amount of light allowed to pass through three different filters—one red, one green, and one blue. LCDs originally used fluorescent bulbs as the backlight, but now most use LEDs (marketers call these products LED LCDs). QD Vision uses quantum dots to enhance the LED backlight.