Improved characteristics and issues of m-plane InGaN films grown on low defect density m -plane freestanding GaN substrates by metalorganic vapor phase epitaxy

Improved quantum efficiency and short radiative lifetime were demonstrated for the near-band-edge emission of nearly stacking-fault-free, 200-250-nm-thick, m -plane pseudomorphic Inx Ga1-x N (0<x0.14) films grown by metalorganic vapor phase epitaxy on the low threading dislocation density (<5× 106 cm-2) freestanding (FS) GaN substrates. Values of full width at half maximum of x-ray ω -rocking curves of the Inx Ga1-x N films remain unchanged as the substrate values being 80 and 60 arcsec for the (10 1- 0) diffraction with 〈 0001 〉 and 〈 11 2- 0 〉 azimuths, respectively, and 80 arcsec for the (10 1- 2) diffraction. As the surface flatness was improved, the incorporation efficiency of In was lower than the cases for c -plane growth and m -plane growth on a defective GaN substrate, according to nonidentical surface kinetics and absence of inclined/tilted planes, respectively.