U.S. researchers to develop new technologies to help improve the efficiency of LED 57%

According to foreign media reports, researchers at the Princeton University have developed a new method that can effectively improve the brightness of LED, light and clarity.

Chou, a professor of electrical engineering at Stephen, led the research team, using nanotechnology to develop a new system PlaCSH. By using the system, the brightness and light efficiency of OLED is improved by 57%, and the definition of LED can be increased by 400%. The researchers say their method should work equally well for LED. The results of this study were published in the August 19th edition of advanced functional materials.

Stephen said that the main problem facing LED is how to reduce the trapped inside the LED structure of light. Although LED is known for its high efficiency, but in fact, the LED emits light only to the light 2%-4%. Trapped in the structure of the light will not only make the LED dark, light effect is reduced, but also make the LED short-lived, because trapped in the LED light will continue to heat, greatly reducing the life of LED.

"The most important thing in the process of making LED is the rate of light extraction," Stephen said. Engineers are trying to overcome this problem by adding metal reflectors, lenses or other components to improve the extraction rate of LED. For OLED, these methods are feasible, the extraction rate can be increased by 38%, but these light extraction technology will make the display reflective, thereby reducing the contrast, so that the image looks blurred. As a result, engineers add light absorbing materials in the display, but Stephen believes that these materials will also absorb the light emitted by the LED, resulting in LED brightness and light efficiency halved.

To this end, Princeton University researchers use nanotechnology to develop a new system PlaCSH, in order to improve the brightness and light efficiency of LED. The figure above shows how the light is trapped in the traditional LED, and how PlaCSH is used to guide the LED light in the new system. The researchers said that the light extraction rate of PlaCSH LED was 60%, higher than the traditional LED by a factor of up to 57%.

The physics behind PlaCSH is complicated, but its structure is simple. In PlaCSH, a luminous material layer is about 100 nm thick is placed in a metal cavity, the cavity is a thin metal film, the other side is the 15 nanometer thick metal mesh, metal wire mesh by 20 nm wide, each net center distance of 200 nm. Stephen said that the price of PlaCSH is very cheap, because it is made of nano imprint, as simple as the press production newspaper.

In addition, Princeton University has been on the use of PlaCSH systems OLED and LED related applications submitted a patent application. (compile /LEDinside Flora)

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