This work examines the effects of polarization-related electric fields on the energy band diagrams, wavelength shift, wave function overlap, and efficiency droop for InGaN quantum wells on various crystal orientations, including polar (0001) (c-plane), semipolar (20-21), semipolar (20-2-1, and nonpolar (10-10) (m-plane). Based on simulations, we show that the semipolar (20-2-1) orientation exhibits excellent potential for the development of high-efficiency, low-droop light-emitting diodes (LEDs). We then present recent advancements in crystal growth, optical performance, and thermal performance of semipolar (20-2-1) LEDs. Finally, we demonstrate a low-droop, high-efficiency single-quantum-well blue semipolar (20-2-1) LED with an external quantum efficiency of more than 50% at 100 A/cm2.
© 2013 IEEE
Daniel F. Feezell, James S. Speck, Steven P. DenBaars, and Shuji Nakamura, "Semipolar (20-2-1) InGaN/GaN Light-Emitting Diodes for High-Efficiency Solid-State Lighting," J. Display Technol. 9, 190-198 (2013)