Quantum dots have unique advantages. By changing the size of the quantum dots, it is possible to precisely control the colors these displays produce, and to tailor this to what the human eye can perceive best, to make the displays even more efficient. Other materials don’t offer this kind of flexibility. Quantum dots can also be made into inks that can be printed using relatively inexpensive, less wasteful techniques.
QD Vision is not the first company to demonstrate a display that uses electrically excited quantum dots as the light-emitting element. Researchers at Samsung did that this spring. But QD Vision is the only company that has publicly committed to using quantum dots as the light-emitting element in a commercial display. LG has partnered with QD Vision to help the company develop its QLED displays.
In the meantime, QD Vision and two other companies, Nanosys and Nanoco, have developed quantum-dot products designed to be added to liquid-crystal displays, in varying formats, in order to improve the efficiency of the conventional light-emitting diode backlight. All these systems use quantum dots to convert light from a blue LED backlight, which is more power efficient than a white one, to red and green light, resulting in white light that is then passed through all the usual filters and other layers in the LCD. The size of this market is about $2 billion a year, estimates Nanoco CEO Michael Edelman. So far, Nanoco is concentrating on this and other applications for quantum dots, including lighting.
The OLED business is not quaking in its boots. Janice Mahon, vice president of technology commercialization at OLED-materials company Universal Display Corporation, says that quantum dots still can’t beat the best OLED materials, particularly in terms of lifetime. But she notes that it’s a young technology and the materials will get better, just as OLED materials did.
Jae-Byung Park, principle engineer at Samsung’s LCD R&D Center in Korea, who has been involved with the company’s quantum-dot efforts, sees another key technical hurdle. “The main issue is cadmium,” he says. The most efficient quantum dots incorporate this toxic element, Park says. European safety standards do not permit the long-term use of cadmium, and the Japanese market is particularly averse to the material. Nanoco stopped using cadmium in its materials several years ago. QD Vision is working on cadmium-free materials, as is Nanosys; Nanoco’s materials have been cadmium-free for a few years.