Performance and polarization effects in (11(2)over-bar2) long wavelength light emitting diodes grown on stress relaxed InGaN buffer layers

Long wavelength (525-575 nm) (11 (2) over bar2) light emitting diodes were grown pseudomorphically on stress relaxed InGaN buffer layers. Basal plane dislocation glide led to the formation of misfit dislocations confined to the bottom of the InGaN buffer layer. This provided one-dimensional plastic relaxation in the film interior, including the device active region. The change of the stress state of the quantum well due to one-dimensional plastic relaxation altered the valence band structure, which produced a significant shift in polarization of emitted light. Devices grown on relaxed buffers demonstrated equivalent output power compared to those for control samples without relaxation. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4753949]