Temperature-dependent growth, photoluminescence and ferromagnetic properties of Co-doped AlN hexagonal nanostructures

Abstract

Co-doped AlN hexagonal nanostructures were synthesized at different temperatures by a facile thermal chemical vapor deposition method. The products exhibit excellent temperature-dependent growth, photoluminescence and ferromagnetic properties. It is found that higher temperature not only facilitates Co incorporation but also increases the density of AlN nucleus, as a result, the morphologies of AlN nanostructures evolve with the increase of temperature. Two photoluminescence bands of samples are centered at 550nm and 425nm, which originate from defects involving VN and O impurities. Co doping may modulate the relative intensity of the emission bands by changing the states of impurities. All Co-doped AlN nanostructures show strong ferromagnetic behaviors which strongly depend on the Co concentration. It is indicated that the multifunctional Co-doped AlN nanostructures have potential applications in optoelectronic and DMSs devices.