Why are Some LEDs More Efficient than Others?
More and more LEDs are being incorporated into technologies for their high energy efficiency, long life, and pure color, but they are not all created equal. It has been found that LEDs using the semiconductor, indium gallium nitride (InGaN), are more efficient than others. This discovery has stirred up a fair amount of debate in the scientific community, but researchers at MIT have recently settled it.
To understand why InGaN LEDs are more efficient, some scientists have put the material under an electron microscope. There they discovered indium-rich clusters, a defect, and so many believe they are responsible for it, but not every is convinced. Some researchers have suggested that it was the high-energy electron beam of the microscope that created those clusters, and that is what the MIT researchers have confirmed. Using a different kind of electron microscope with lower energy beams, the researchers were able to capture sub-nanometer details without damaging the InGaN sample, and no indium clusters were found.
While this is definitely a blow to those hoping it was the indium clusters that led to the high efficiency, this research is truly a benefit to the science as everyone can refocus on what the cause actually is. Helping that new research will be the microscopy method used for this study, as it does not disturb InGaN samples.