The effect of V/III ratio on the growth and properties of AlGaN layers grown on (11 (2) over bar2) AlN templates grown on (10 (1) over bar0) sapphire by metalorganic vapour phase epitaxy was studied. The surface morphology of the (11 (2) over bar2) AlGaN layers and the (11 (2) over bar2) AIN templates showed an undulation along [1 (1) over bar 00](AlGaN,AlN). The Al-content and thickness of the layers increased with decreasing V/III ratio due to a reduction in the parasitic reactions of the precursors. The Al-content of the (11 (2) over bar2) layers was found to be in the range of 29.5-47.9%, which is lower than the composition of the simultaneously grown (0001) reference layers (30.4-58.0%). This was attributed to a higher density of cation (nitrogen) dangling bonds on the (11 (2) over bar2) surface. Low temperature photoluminescence measurements of the (11 (2) over bar2) layers showed an emission wavelength that shifts gradually from 273 nm to 306 nm with increasing V/III ratio. A decreased PL intensity of the layers with decreasing V/III ratio was attributed to an increase in cation vacancies. The Stokes-shift of the (11 (2) over bar2) layers was estimated to be about 60-194 meV, and this shift increases with increasing Al-content (decreasing V/III ratio) correlated to an increased exciton localization. (C) 2015 Elsevier B.V. All rights reserved.