کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1331401 | 1500118 | 2013 | 7 صفحه PDF | دانلود رایگان |

TaON is considered as a potential candidate as a visible-light responsive photocatalyst. We report the results of ab initio studies of electronic structure of TaON-based alloys. Specifically, we show that the position of conduction and valence band can be modified by varying the oxygen and nitrogen concentrations in TaO1−xN1+x. We find that the band gap decreases monotonically with the increase of N/O ratio. The band gap energy is decreased in monoclinic TaON from near 2.3 eV to just over 1.7 eV (i.e., by 35%) when N/O ratio is increased from 3/5 to 5/3. Our calculations show that the band gap reduces in a series of experimentally fabricated alloys ZrTa3O5N3→TaON→YTa7O7N8. The band gap reduction is mostly associated with the change in the position of the valence band due to the hybridization of N 2p states, while the conduction band consisting mostly of Ta 5d-states is not sensitive to N content. The calculated optical absorption spectra show reduction in the optical band gap with increasing N/O ratio.
Band gap energy of TaO1−xN1+x as a function of N/O ratio.Figure optionsDownload as PowerPoint slideHighlights
► The electronic and optical properties of TaON-based alloys are studied using DFT.
► The position of conduction and valence bands can be modified by varying N/O ratio.
► The band gap decreases monotonically with the increase of N/O ratio in TaO1−xN1+x.
► The band gap reduces in a series of fabricated alloys ZrTa3O5N3→TaON→YTa7O7N8.
► The optical band gap decreases with the increase of N/O ratio.
Journal: Journal of Solid State Chemistry - Volume 198, February 2013, Pages 337–343