Effect of Se Isoelectronic Impurity on the Luminescence Features of the ZnO

Se-doped ZnO films have been deposited on the sapphire substrates by the radio-frequency magnetron sputtering technique. An influence of the isoelectronic impurity Se on the room-temperature luminescence of the ZnO films is studied. It is revealed that the Se doping leads to an appearance of the intense near-band edge emission spectrum, which consists of three emission bands. The dominant emission band is related to the recombination of the bound excitons. The radiation caused by the band-to-band transitions of free carriers is observed in the high-energy side of the spectrum ((h) over bar omega > E-g).