Screened hybrid density functional study on Nb- and Ta-doped TiO 2
2012; American Physical Society; Volume: 85; Issue: 3 Linguagem: Inglês
10.1103/physrevb.85.033104
ISSN1550-235X
Autores Tópico(s)Copper-based nanomaterials and applications
ResumoAnatase- and rutile-type Nb- and Ta-doped TiO${}_{2}$ compounds have different electronic properties. While doped anatase TiO${}_{2}$ is a transparent metallic material, doped rutile TiO${}_{2}$ behaves as a semiconductor. Density-functional calculations within the (semi)local-density approximation predict the metallization of both anatase and rutile TiO${}_{2}$ with Nb or Ta doping while the on-site Coulomb correction has prevented metallization in both systems. We present screened-hybrid-density-functional calculations of Nb- and Ta-doped TiO${}_{2}$. The calculations show that doped anatase TiO${}_{2}$ is metallic, and doped rutile TiO${}_{2}$ is a semicondutor with the in-gap state related to a Ti${}^{3+}$ species. The difference in the electronic states of the Nb- and Ta-doped TiO${}_{2}$ is clearly shown.
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