Substrates sapphire, dislocation types

In this section, as examples of nonpolar GaN on lattice-mismatched substrates, the surface morphology and microstructure of a-plane GaN on an r-plane sapphire substrate and m-plane GaN on m-plane 4H-SiC are presented. Next, the SELO method of reducing threading-dislocation and stacking-fault densities is described in detail. This is followed by a description of the properties of the conductivity control of n-type andp-type nonpolar GaN, and the growth of the heterostructure/quantum well structure. Finally, the performances of the violet and green LEDs on nonpolar GaN are discussed with respect to the threading-dislocation density dependence of the output power. 

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