Effect of Mg doping on growth and photoluminescence of AlN hexagonal nanorods

Highlights: • Pure and Mg-doped AlN hexagonal nanorods were synthesized successfully. • Mg incorporation promoted not only axial but also radial growth rate of AlN HNRs. • Mg doping has modulated the native point defects states which changed the relative intensity of peaks. - Abstract: Pure and Mg-doped AlN hexagonal nanorods (HNRs) were synthesized by a simple thermal chemical vapor deposition process without structure-directing templates or catalysts. Mg incorporation promoted not only axial but also radial growth rate of AlN HNRs compared to undoped sample. The corresponding optical properties of the products were investigated by room-temperature photoluminescence (PL) measurement. Quite broad ultraviolet emission bands centered at 280 nm and 330 nm for AlN HNRs and AlN:Mg HNRs, respectively, were observed. Multi-peak fitting analysis shows that various defects conduced to the broad emission bands of the two samples, and Mg doping has increased the proportion of V_N which changed the relative intensity of peaks, instead of forming Mg impurity energy levels that directly affect luminescence