Optical properties and microstructure of nitrogen-doped SrTiO3.

Nitrogen-doped SrTiO3 samples have been successfully prepared by nitrogen-ion implantation. X-ray photoelectron spectra clearly indicate the presence of nitrogen dopants in the crystal lattice of SrTiO3. The ultraviolet–visible absorption spectra of nitrogen-doped SrTiO3 show enhanced visible light absorption in the range of 400–500 nm, which contributs to the localized N 2p state in the band gap of SrTiO3. The resistance coefficient of temperature is positive indicating metallic conducting behavior. The nonlinear dependence of voltage on current at liquid-nitrogen temperatures indicates a possible energy barrier in the grain boundary.PACS Nos.: 72.20.–i, 72.80.Ga, 78.20.–e [ABSTRACT FROM AUTHOR]