High power and high efficiency blue light emitting diode on freestanding semipolar (10 1̄1̄) bulk GaN substrate

Abstract

Blue InGaNGaN multiple-quantum-well light emitting diodes with a peak emission wavelength of 444 nm were grown on low extended defect density semipolar (10 1- 1-) bulk GaN substrates by conventional metal-organic chemical vapor deposition. The calculated external quantum efficiency and output power at a drive current of 20 mA under pulsed operations (10% duty cycle) were 29% and 16.21 mW, respectively. The device exhibited virtually no peak electroluminescence wavelength shift with increasing drive currents, indicating a significant reduction of polarization-related internal electric fields. © 2007 American Institute of Physics.