Effect of nitrogen doping on optical properties and electronic structures of SrZrO3 films

The effect of nitrogen doping on optical properties and electronic structures of SrZrO3 (SZO) films was investigated both experimentally and theoretically. A shift of the absorption edge to the longer wavelength, i.e., the narrowing of the band gap caused by nitrogen doping was observed. The first-principles calculations revealed that the band gap reduced in nitrogen-doped SZO because of the localized N 2p states above O 2p states and the bottom of conduction band of Zr 4d shifting to a lower energy.

Research highlights
► A shift of the absorption edge to longer wavelength in N-doped SrZrO3 film.
► The experimental results show a 0.08 eV reduction of band gap in N-doped film.
► The first-principles calculations are used to analyze the impact of N-doping.
► N 2p states localized above O 2p states and Zr 4d shifted to a lower energy.