MOVPE of (In)GaN on ScAlMgO4 substrates toward long wavelength optical devices

ScAlMgO4 (0001) is a substrate material suitable for heteroepitaxy of In0.17Ga0.83N because lattice matching can be achieved. Although direct growth of In0.17Ga0.83N layers on ScAlMgO4 (0001) substrates is ideal, direct growth by metalorganic vapor phase epitaxy results in nitrogen polarity. In contrast, In0.17Ga0.83N low temperature buffer layers can flip the polarity. On the group-III-polar In0.17Ga0.83N/ScAlMgO4 templates red-emitting quantum wells (QWs) and LEDs were fabricated. The QWs had much better internal quantum efficiencies than those on conventional GaN/sapphire templates, and electrical drive of LEDs was demonstrated.