First principle study of Ce doping and related complexes in GaN

► Electronic structures and optical properties of Ce doping in GaN are calculated by first-principle method. ► The CeGa substitutional in GaN introduces a localized impurity band from Ce-4f in the bandgap. ► The incorporation of Ce impurity in GaN can lead to the magnetic order. ► The Ce dopants in GaN gives rise to new peaks in the low energy regions of dielectric function and absorption spectrum.