Magnetic properties and photoluminescence of undoped and transition metal doped A1N nanorods

The undoped and transition metal (TM) -doped AIN (AIN:Cu and AIN:Fe) nanorods on silicon substrates were fabricated using a catalysis-free vapor phase method. All the nanorods exhibited high crystalline quality and preferred c-axis orientation. Room-temperature photoluminescence (PL) measurement revealed that undoped AIN nanorods exhibited strong oxygen-related impurity emission at ~3.25 eV. However, AIN:Fe nanorods had two strong ultraviolet emissions at 3.69 and 6.02 eV which could be attributed to Fe ³⁺-related and band-edge emission, respectively. Both the Cu and Fe-doped AIN nanorods are ferromagnetic. The spontaneous saturated magnetization of the AIN:Cu and AIN:Fe nanorods were determined to be 0.38 and 3.5 emu/cm³ at room temperature, respectively. The Fe-doped AIN nanorods not only exhibited ferromagnetism but also significantly enhanced the band-edge emission as compared to the undoped AIN nanorods.