Demonstration of a semipolar (10(1)over-bar1(3)over-bar) InGaN/GaN green light emitting diode

We demonstrate the growth and fabrication of a semipolar (10 (13) over bar) InGaN/GaN green (similar to 525 nm) light emitting diode (LED). The fabricated devices demonstrated a low turn-on voltage of 3.2 V and a series resistance of 14.3 Omega. Electroluminescence measurements on the semipolar LED yielded a reduced blueshifting of the peak emission wavelength with increasing drive current, compared to a reference commercial c-plane LED. On-wafer measurements yielded an approximately linear increase in output power with drive current, with measured values of 19.3 and 264 muW at drive currents of 20 and 250 mA,respectively. The external quantum efficiency did not decrease appreciably at high currents. Polarization anisotropy was also observed in the electroluminescence from the semipolar green LED, with the strongest emission intensity parallel to the [1 (2) over bar 10] direction. A polarization ratio of 0.32 was obtained at a drive current of 20 mA. (c) 2005 American Institute of Physics.