Effect of the growth temperature on the properties of AlxGal−xN epilayers grown by HVPE

► Growth temperature of AlxGa1−xN epilayers was varied from 1050 to 1090 °C by a HVPE system. ► Crystallinity of AlxGa1−xN epilayers was improved with the increase of growth temperature. ► As the growth temperature was increased, compositional non-uniformity also disappeared. ► AlxGa1−xN epilayers grown at 1090 °C showed the best surface roughness and crystallinity.