LED lighting is demonstrating compelling value to buyers, enabling ever-increasing adoption and energy savings. Over the past decade, research and development have yielded impressive improvements in the cost, color performance, light output, efficacy, reliability, lifetime, and manufacturability of LED products. But despite the rapid pace of its development, LED lighting has not yet come close to achieving its full potential. Significant work remains to be done to further improve performance, reduce costs, and efficiently enable new value propositions such as improved health, productivity, and safety.
LEDs are semiconductor devices that produce light when an electrical current flows through them. Optimizing efficiency in LED lighting will hinge on ongoing improvements to light-generating materials (LEDs and phosphors) and system integration. LED package prices have declined to the point where they are typically no longer the primary cost component of the integrated lighting product. Now, LED package and luminaire system integration improvements can have a larger impact on the cost of LED lighting. However, solving technical challenges at the LED can still have a big impact on cost and efficiency, and enable new lighting value and applications. One package-integration direction has been to increase light output from a given package size to decrease cost, while another has been to drive LED material at lower current densities and use lower-cost packaging materials.
There are still many fundamental technical challenges that need to be met to achieve DOE cost and efficacy goals. For example, the process of down-conversion – whether with phosphors or quantum dots – offers room for improvement. Alternatively, improved green, amber, and red LEDs can reduce phosphor-conversion losses and enable color control. This alternative approach for creating white light using color-mixed LEDs offers another path to high efficiency and the possibility of color tunability. In addition, work remains to be done in such areas as current efficiency droop, color shift, and system reliability, as well as in light distribution, dimming, thermal management, and power supply performance. Luminaire cost, performance, and design flexibility can also be improved by reducing efficiency losses at higher temperature and drive current operation conditions.