Featured Research

from universities, journals, and other organizations

Grass really is greener on TV, computer screens, thanks to quantum dots


Date:
August 8, 2014
Source:
American Chemical Society (ACS)
Summary:
High-tech specks called quantum dots could bring brighter, more vibrant color to mass market TVs, tablets, phones and other displays. A new technology called 3M quantum dot enhancement film (QDEF) that efficiently makes liquid crystal display (LCD) screens more richly colored is described by an expert.

Quantum dots make greens and reds pop on screens (left) compared with other types of displays (right).
Credit: 3M

High-tech specks called quantum dots could bring brighter, more vibrant color to mass market TVs, tablets, phones and other displays. Today, a scientist will describe a new technology called 3M quantum dot enhancement film (QDEF) that efficiently makes liquid crystal display (LCD) screens more richly colored.

His talk will be one of nearly 12,000 presentations at the 248th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society, taking place here through Thursday.

"Green grass just pops out at you from these displays," says Eric Nelson, Ph.D., who helped create the plastic films that hold the quantum dots in a screen. "We believe this is the most efficient way to get to a high-color display."

That's because quantum dot, or "QD," displays need less energy compared to other high-color options. QDs are superconducting crystals so small that 10,000 could fit across the width of a human hair.

Almost all electronics sold today, from TVs to smartphones, use LCDs. A typical LCD works by shining white light through a series of fliters that produce the colors the viewer sees. To achieve the best color, these filters need to be fairly dark. However, it takes a lot of energy to make the light bright enough for the viewer's eye. The other problem, says Nelson, who is at the 3M Company, is that "you always tend to leak a bit of green into red, and blue into green, and so forth. So instead of ending up with a very pure red, you end up with an orange-y color. It's difficult to get roses or apples to look very red on a conventional LCD."

Rather than filtering light, QDs change it into a different color. The dots -- made for 3M by Nanosys, Inc. -- produce specific colors of light based on how big they are. In 3M QDEF displays, the LCD's white backlight is replaced with a blue one, and a sheet of plastic embedded with QDs that produce red and green light is placed over it. The display combines these three colors to produce all the colors the viewer sees.

One drawback of the dots is that they break down quickly when exposed to water and oxygen in the air. To address this challenge, Nelson helped create the plastic sheathing that protects them. They sandwiched the QDs between two polymer films, with the QDs embedded in an epoxy glue. "The polymer/quantum dot sandwich looks like a piece of plastic film," says Nelson. Coatings on the film provide further protection and enhance the viewing experience.

Nelson also will describe the environmental advantages of the technology. Because the QDEF displays need less light, they consume less electricity and help device batteries last longer than other high-color solutions. He says 3M's tests have shown that the dots' heavy metals -- many of which are already found in today's electronics -- are entirely sealed inside the film. That means they won't leach out during the products' lifetime or as they languish in landfills if the displays aren't recycled.

3M hopes QDEF technology will compete well with more costly displays like those that use organic light-emitting diodes (OLEDs). Nelson explains that OLEDs produce similarly brilliant colors to the QDEF displays, but they use individual lights to make different colors. The drawback to OLEDs is that they are much more costly to manufacture.

Although QDEF displays are more expensive than conventional low-color LCDs, Nelson says the cost will come down as the technology becomes more widespread and as manufacturing costs come down with increased production scale. Several devices featuring QDEF are already on the market, and more are on the way.


Story Source:

The above story is based on materials provided by American Chemical Society (ACS). Note: Materials may be edited for content and length.


Cite This Page:

American Chemical Society (ACS). "Grass really is greener on TV, computer screens, thanks to quantum dots
." ScienceDaily. ScienceDaily, 8 August 2014. <www.sciencedaily.com/releases/2014/08/140808110028.htm>.
American Chemical Society (ACS). (2014, August 8). Grass really is greener on TV, computer screens, thanks to quantum dots
. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2014/08/140808110028.htm
American Chemical Society (ACS). "Grass really is greener on TV, computer screens, thanks to quantum dots
." ScienceDaily. www.sciencedaily.com/releases/2014/08/140808110028.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins