中文摘要：

By using spin-polarized density functional theory calculations,the electron density differences,band structures and density of states of p-type N-doped PbTiO3 have been studied.In addition,the oxygen vacancy in N-doped PbTiO3 is also discussed.After the nitrogen dopant is introduced into the crystal,the N-doped PbTiO3system is spin-polarized,the spin-down valance bands move to a high energy level and the Fermi energy level moves to the top of the valance bands,finally the band gap is narrowed.In this process,the N-doped PbTiO3 shows typical p-type semiconductor characteristics.When an oxygen vacancy and N impurity coexist in PbTiO3,there is no spin-polarized phenomenon.The conduction bands move downward and the acceptors are found to be fully compensated.The calculation results are mostly consistent with the experimental data.

英文摘要：

By using spin-polarized density functional theory calculations, the electron density differences, band structures and density of states of p-type N-doped PbTiO3 have been studied. In addition, the oxygen vacancy in N-doped PbTiO3 is also discussed. After the nitrogen dopant is introduced into the crystal, the N-doped PbTiO3 system is spin-polarized, the spin-down valance bands move to a high energy level and the Fermi energy level moves to the top of the valance bands, finally the band gap is narrowed. In this process, the N-doped PbTiO3 shows typical p-type semiconductor characteristics. When an oxygen vacancy and N impurity coexist in PbTiO3, there is no spin-polarized phenomenon. The conduction bands move downward and the acceptors are found to be fully compensated. The calculation results are mostly consistent with the experimental data.