High external quantum efficiency (6.5%) InGaN V-defect LEDs at 600 nm on patterned sapphire substrates
Jacob Ewing, Cheyenne Lynsky, Matthew S. Wong, Feng Wu, Yi Chao Chow, Pavel Shapturenka, Michael Iza, Shuji Nakamura, Steven P. DenBaars, James S. Speck
Abstract
Highly efficient long-wavelength InGaN LEDs have been a research focus in nitride LEDs for their potential applications in displays and solid-state lighting. A key breakthrough has been the use of laterally injected quantum wells via naturally occurring V-defects which promote hole injection through semipolar sidewalls and help to overcome the barriers to carrier injection that plague long wavelength nitride LEDs. In this article, we study V-defect engineered LEDs on (0001) patterned sapphire substrates (PSS) and GaN on (111) Si. V-defects were formed using a 40-period InGaN/GaN superlattice and we report a packaged external quantum efficiency (EQE) of 6.5% for standard 0.1 mm 2 . LEDs on PSS at 600 nm. We attribute the high EQE in these LEDs to lateral injection via V-defects.