Band-edge exciton transitions in (Ga_1-xMn_x)N diluted magnetic semiconductor films with above room temperature ferromagnetic transition

(Ga_1-xMn_x)N thin films grown on GaN buffer layers by using molecular beam epitaxy were investigated with the goal of producing diluted magnetic semiconductors (DMSs) with band-edge exciton transitions for applications in optomagnetic devices. The magnetization curve as a function of the magnetic field at 5 K indicated that ferromagnetism existed in the (Ga_1-xMn_x)N thin films, and the magnetization curve as a function of the temperature showed that the ferromagnetic transition temperature of the (Ga_1-xMn_x)N thin film was above room temperature. Photoluminescence and photoluminescence excitation spectra showed that band-edge exciton transitions in (Ga_1-xMn_x)N thin films appeared. These results indicate that the (Ga_1-xMn_x)N DMSs with a magnetic single phase hold promise for potential applications in spin optoelectronic devices in the blue region of the spectrum.