The revolutionary solid-state lighting technology will enable LED to be more widely used

LED with power saving characteristics become more and more popular solid-state lighting program, technology evolution will make the application of LED more widely. Rensselaer Polytechnic Institute (RPI) researchers lighting engineering research center of intelligence through the use of new materials, set out on a "revolutionary" solid state lighting technology research.

Now the LED is using gallium nitride indium as the active area of quantum well (quantum wELls) material, sandwiched between the thick Gan barrier layer (barrier layers). The corresponding fragments (relative fraction) between the two materials can make the color of the light purple to amber. The polarization mismatch (polarization mismatch) between the two materials can lead to electron leakage and reduce the effectiveness of LED at high output levels. Gallium nitride is a relatively simple material, but it will not form polarization matching with Gan gan. "The mismatch is the physical cause of high output power LED efficiency (Efficiency droop)," said Fred Schubert, a research leader at the RPI Center for intelligent lighting engineering. The high efficiency of the output power LED sudden drop phenomenon, so that the output power of such products is higher, the energy consumption per lumen more. Schuert pointed out that this is a key disadvantage of solid-state lighting technology in the market. "The high output power of LED for the past ten years are using the same material, our new scheme is to change the existing LED (active region) activity in the area of key elements, I believe this change will be the solid-state lighting technology reform all over the world. He expects the new technology in the current size of $10 billion in the global LED market, the application of 75% of the product.

Schuert's team claimed that they were able to replace gallium nitride by using a polarization matched gallium nitride layer, so that the efficiency of the crash could be reduced to 25% at high power. Large scale polarization mismatch between materials means that electrons will start to run with the current, and then move back and forth with the current when they move to a position where they can be recombined. By matching these polarization fields, not only can the efficiency of the LED be improved, but also the forward voltage (forward voltage) can be reduced. Schuert said that the use of polarization matching materials to bring a lot of change, although not perfect, but they believe in the field of solid-state lighting for high power LED applications is very important. The ideal LED efficiency should be around 300 lumens per watt, but even the most efficient experimental prototype, its efficiency is only up to 170 lumens per watt. Schuert's research team also has a member from Samsung, Samsung and RPI together, Schubert is confident that within a few years can produce 200 lumens per watt LED products.