Optimizing optical absorption of Ti O2 by alloying with Ti S2

Naoto Umezawa; Anderson Janotti; Patrick Rinke; Toyohiro Chikyow; Chris G. Van De Walle

doi:10.1063/1.2835707

Optimizing optical absorption of Ti O2 by alloying with Ti S2

Naoto Umezawa, Anderson Janotti, Patrick Rinke, Toyohiro Chikyow, Chris G. Van De Walle

Research output: Contribution to journal › Article › peer-review

24 Citations (Scopus)

Abstract

Ti O2 is an attractive material for photocatalytic water splitting, but its band gap is too large to allow for efficient absorption of solar photons. We present a comprehensive first-principles investigation of band-structure modifications induced by alloying Ti O2 with Ti S2. The band gap of Ti O2 (1-x) S2x alloys exhibits a dramatic decrease upon addition of even a low concentration of S. The optical absorption of visible light is attainable with sulfur concentrations less than x=0.25. We have verified that the band alignment in these alloys is favorable for photocatalytic applications: in particular, the conduction band exhibits only small shifts, while the majority of the band-gap change is due to an upward shift of the valence band.

Original language	English
Article number	041104
Journal	Applied Physics Letters
Volume	92
Issue number	4
DOIs	https://doi.org/10.1063/1.2835707
Publication status	Published - 2008
Externally published	Yes

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

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title = "Optimizing optical absorption of Ti O2 by alloying with Ti S2",

abstract = "Ti O2 is an attractive material for photocatalytic water splitting, but its band gap is too large to allow for efficient absorption of solar photons. We present a comprehensive first-principles investigation of band-structure modifications induced by alloying Ti O2 with Ti S2. The band gap of Ti O2 (1-x) S2x alloys exhibits a dramatic decrease upon addition of even a low concentration of S. The optical absorption of visible light is attainable with sulfur concentrations less than x=0.25. We have verified that the band alignment in these alloys is favorable for photocatalytic applications: in particular, the conduction band exhibits only small shifts, while the majority of the band-gap change is due to an upward shift of the valence band.",

author = "Naoto Umezawa and Anderson Janotti and Patrick Rinke and Toyohiro Chikyow and {Van De Walle}, {Chris G.}",

note = "Funding Information: This work was supported in part by the NSF MRSEC Program under Award No. DMR05-20415 and by the UCSB Solid State Lighting and Energy Center. N. U. thanks the California Nanosystems Institute (CNSI) for its hospitality. All the calculations were performed on the CNSI computer facilities of Hewlett-Packard clusters. Copyright: Copyright 2008 Elsevier B.V., All rights reserved.",

year = "2008",

doi = "10.1063/1.2835707",

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AU - Umezawa, Naoto

AU - Janotti, Anderson

AU - Rinke, Patrick

AU - Chikyow, Toyohiro

AU - Van De Walle, Chris G.

N1 - Funding Information: This work was supported in part by the NSF MRSEC Program under Award No. DMR05-20415 and by the UCSB Solid State Lighting and Energy Center. N. U. thanks the California Nanosystems Institute (CNSI) for its hospitality. All the calculations were performed on the CNSI computer facilities of Hewlett-Packard clusters. Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2008

Y1 - 2008

N2 - Ti O2 is an attractive material for photocatalytic water splitting, but its band gap is too large to allow for efficient absorption of solar photons. We present a comprehensive first-principles investigation of band-structure modifications induced by alloying Ti O2 with Ti S2. The band gap of Ti O2 (1-x) S2x alloys exhibits a dramatic decrease upon addition of even a low concentration of S. The optical absorption of visible light is attainable with sulfur concentrations less than x=0.25. We have verified that the band alignment in these alloys is favorable for photocatalytic applications: in particular, the conduction band exhibits only small shifts, while the majority of the band-gap change is due to an upward shift of the valence band.

AB - Ti O2 is an attractive material for photocatalytic water splitting, but its band gap is too large to allow for efficient absorption of solar photons. We present a comprehensive first-principles investigation of band-structure modifications induced by alloying Ti O2 with Ti S2. The band gap of Ti O2 (1-x) S2x alloys exhibits a dramatic decrease upon addition of even a low concentration of S. The optical absorption of visible light is attainable with sulfur concentrations less than x=0.25. We have verified that the band alignment in these alloys is favorable for photocatalytic applications: in particular, the conduction band exhibits only small shifts, while the majority of the band-gap change is due to an upward shift of the valence band.

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Optimizing optical absorption of Ti O2 by alloying with Ti S2

Abstract

ASJC Scopus subject areas

UN SDGs

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