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A patterned GaN/sapphire template with separate regions angled between 0.4 and 2 to the wurtzite c-plane was used to grow a 50 nm In 0:1 Ga 0:9 N layer. The photoluminescence wavelength varied between 403 and 389 nm according to the increased region's angle. The indium content measured using X-rays was reduced in regions with a higher miscut angle. Patterned freestanding GaN with separate regions angled by 0.35 and 0.85 to the c-plane was used to fabricate ridge-waveguide diode lasers. Each laser stripe was placed inside one of the angled regions. Lasing wavelengths of 405:8 AE 0:2 and 401:0 AE 1 nm were obtained for devices grown in those regions.

Measurements of photoluminescence and its dependence on hydrostatic pressure are performed on a set of InN/nGaN superlattices with one InN monolayer and with different numbers of GaN monolayers. The emission energies, EPL, measured at ambient pressure, are close to the value of the band gap, Eg, in bulk GaN, in agreement with other experimental findings. The pressure dependence of the emission energies, dEPL/dp, however, resembles that of the InN energy gap. Further, the magnitudes of both EPL and dEPL/dp are significantly higher than those obtained from ab-initio calculations for 1InN/nGaN superlattices. Some causes of these discrepancies are suggested.