Two UCLA researchers are working to brighten the future of television and cell phone screens.
Materials science and engineering professor Yang Yang and his graduate researcher Jinsong Huang are working to make more efficient LEDs, or light-emitting diodes.
LEDs are used to illuminate technological items including TVs and cell phone display screens.
The researchers are using polymer, a kind of plastic, to improve the LEDs. Specifically, they are working on making the individual elements, or devices, of a pixel more efficient, which will lead to brighter display screens.
Yang and Huang take the polymer and dissolve it until it becomes ink, which is then used to form a display that forms an image for viewers.
“One unique thing we are doing: We are using a cheap process to make this device,” Huang said.
The cost of this method is less than half of what it would be with the conventional LED, Yang said. Though the retail price of the products has not yet been determined, the new technology will lower prices of items such as computer monitors.
LEDs are normally described in terms of lumens per watt. Each color has a different lumen per watt, which measures how bright a device is and how much power it consumes.
A red color on a cell phone display is five lumens per watt. With their new devices, Yang and Huang have made it 20 lumens per watt, a four-fold increase.
“We are making them more efficient,” Yang said.
He said the ultimate goal is to make each color 80 lumens per watt.
The effects of the new technology can be seen in a variety of electronic devices. For example, the display for a laptop drains a significant amount of the computer’s battery power. Since the device Yang and Huang created is more efficient, it will use less power, increasing the battery life of the laptop. Yang said the invention could potentially increase the life of a two-hour battery to four hours.
This invention is expected to change the way the conventional LED works and may be seen in the market within the next three years, Huang said. He added that Canon, the researchers’ sponsor, hopes to use the new technology in its products within that time frame.
The conventional LED requires eight to 10 layers of backlights and filters, but Yang and Huang’s technology uses a simpler, single-layer structure.
“We don’t need (the layers),” Huang said. “It can be much thinner and also much brighter without (them).”
Yang said this invention is also more environmentally friendly because unlike current LEDs, the one they have created does not use mercury. For example, once a computer screen is thrown away, the mercury from the LEDs will pollute the underground water, Yang said.
Both Yang and Huang said they are pleased with their work so far and are enjoying what they are doing.
“I think it’s fun; it’s great,” Yang said. “When you can see the effects of your research, it’s very interesting.”
Huang said working with LEDs was ideal for him because it fits his background with optoelectronic devices, which involves studying the application of electronics that use light.
“The next step is we are trying to make the LED devices have a longer life,” Huang said.