Electronic structure and enhanced visible light absorption of N, B-codoped TiO2

TL;DR

This study uses GGA+U calculations to analyze how N, B codoping in TiO2 modifies its electronic structure and enhances visible light absorption, highlighting the significance of specific dopant configurations.

Contribution

It provides detailed insights into the electronic and optical effects of different N, B codoping configurations in TiO2, identifying the NsBi configuration as most effective for visible light absorption.

Findings

NsBi codoped TiO2 produces significant mid-gap states.

Only NsBi configuration shows obvious visible optical transition.

Codoping shifts optical band edges slightly into visible region.

Abstract

We present the GGA+U calculations to investigate the electronic structure and visible light absorption of the N, B-codoped anatase TiO2. The NsBi (substitutional N, interstitial B) codoped TiO2 produces significant Ti 3d and N 2p mid-gap states when the distance of N and B atoms is far, and the NiBi (interstitial N and B) and NsBs (substitutional N and B) codoped TiO2 prefer to form localized p states at 0.3-1.2 eV above the valence band maximum. Further, the optical band edges of the three codoped systems shift slightly to the visible region, but only the far distance NsBi codoped TiO2 shows an obvious visible optical transition. These results indicate that the NsBi codoped TiO2 has a dominant contribution to the visible absorption of the N, B-codoped TiO2.