With the assistance of a research institute outside the company, tests were performed to measure the luminous efficiency of an LED element using NGK’s new GaN wafer. With an injection current of 200mA, the GaN wafer during the tests showed an internal quantum efficiency of 90%. The GaN wafer achieved a luminous efficiency of 200lm/W, which is twice as efficient as those on the market today. This in affect means that with this new solution the power consumption can be reduced by up to 50%, while upholding the same brightness of a traditional LED.
Since the amount of current can potentially be cut into half while still retaining the same brightness, this will also reduce the heat generation within the LED’s. Less heat will in turn increase the lifetime of the LED’s, and also enables lighting equipment to become smaller and more compact. LED’s are already becoming an viable alternative to the more traditional, and energy inefficient lighting systems, but NGK Insulators, Ltd with their GaN wafers clearly show there is still more we can do to reduce our daily energy consumption.
NGK Insulators Ltd, established a new department named “Wafer Project” in April this year, aiming to promptly start commercializing the wafer products. The plan is to launch the first shipment of sample products of a 4-inch-diameter GaN wafer within this year, making it the world’s first 4-inch-diameter GaN wafer produced with the new liquid phase epitaxial growth technology.
NGK is also accelerating the development of GaN wafers with lower defect density and of larger diameter (6 inches). These are intended for use in hybrid cars, electric vehicles and power amplifiers for cellular base stations.