Prospective emission efficiency and in-plane light polarization of nonpolar m-plane InxGa1−xN∕GaN blue light emitting diodes fabricated on freestanding GaN substrates

Prospective equivalent internal quantum efficiency $\left({\eta }_{\mathrm{int}}\right)$ of approximately 34% at $300\mathrm{K}$ was demonstrated for the blue emission peak of nonpolar $m$ -plane $\left(1\overline{1}00\right)$ ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ multiple quantum well light emitting diodes (LEDs) fabricated on freestanding $m$ -plane GaN substrates. Although the ${\eta }_{\mathrm{int}}$ value is yet lower than that of conventional $c$ -plane blue LEDs $(>70\%)$ , the results encourage one to realize high performance green, amber, and red LEDs by reducing the concentration of nonradiative defects, according to the absence of the quantum-confined Stark effects due to the polarization fields parallel to the quantum well normal. The electric field component of the blue surface emission was polarized perpendicular to the $c$ axis with the in-plane polarization ratio of 0.58 at $300\mathrm{K}$ .