NGK Insulators doubles green LED light efficiency on GaN wafers

Electronic enthusiasts Reuters [Translate / Joyce] NGK Insulators headquartered in Nagoya, Japan developed a gallium nitride (GaN) wafer, the alleged original green LED luminous efficiency can be doubled. NGK uses an independent patented liquid phase epitaxy technology to reduce the defect density during the single crystal growth stage. The company says that all of their 2-inch diameter GaN wafers have low defect densities and are colorless and transparent.

GaN wafer, 2 inches on the left and 4 inches on the right

According to a joint study between the company and Nagoya University, the green LED chip on the NGK GaN wafer achieved an internal quantum efficiency of 60% (the injected current density per square centimeter is approximately 200 amperes). This efficiency is about twice that of the green LED chips currently on the market. The company announced this result at the Nitride Semiconductors International Symposium (IWN2012) held in Sapporo, Hokkaido, Japan from October 14 to 19 this year.