Optical absorption and spectral photoconductivity in α-(Fe1-xCrx)2O3 solid-solution thin films

被引：41

作者：

Chamberlin, Sara E. ^{[1
]}

Wang, Yong ^{[1
]}

Lopata, Kenneth ^{[2
]}

Kaspar, Tiffany C. ^{[1
]}

Cohn, Alicia W. ^{[3
]}

Gamelin, Daniel R. ^{[3
]}

Govind, Niranjan ^{[2
]}

Sushko, Peter V. ^{[4
,5
]}

Chambers, Scott A. ^{[1
]}

机构：

[1] Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, Richland, WA 99352 USA

[2] Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA

[3] Univ Washington, Dept Chem, Seattle, WA 98195 USA

[4] UCL, Dept Phys & Astron, London WC1E 6BT, England

[5] UCL, London Ctr Nanotechnol, London WC1E 6BT, England

来源：

JOURNAL OF PHYSICS-CONDENSED MATTER | 2013年 / 25卷 / 39期

基金：

美国国家科学基金会;

关键词：

WATER; ALPHA-FE2O3; PHOTOCATALYSIS; OXIDES;

D O I：

10.1088/0953-8984/25/39/392002

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

Hematite, alpha-Fe2O3, is an attractive narrow gap oxide for consideration as an efficient visible light photocatalyst, with significant potential for band gap engineering via doping. We examine optical absorption in alpha-(Fe1-xCrx)(2)O-3 epitaxial films and explain the observed excitations, and the nature of the band gap dependence on x, through first-principles calculations. The calculated and measured optical band gap becomes smaller than that of bulk alpha-Fe2O3 and reaches a minimum as the Cr cation fraction increases to 50%. The lowest energy transitions in the mixed-metal alloys involve electron excitation from occupied Cr 3d orbitals to unoccupied Fe 3d orbitals, and they result in a measurable photocurrent. The onset of alpha-Fe2O3 photoconductivity can be reduced by nearly 0.5 eV (to 1.60 eV) through addition of Cr.

引用

页数：6

共 21 条

[1] Visible-light photocatalysis in nitrogen-doped titanium oxides [J].

Asahi, R ;

Morikawa, T ;

Ohwaki, T ;

Aoki, K ;

Taga, Y .

SCIENCE, 2001, 293 (5528) :269-271

[2]

Dotan H, 2013, NAT MATER, V12, P158, DOI [10.1038/NMAT3477, 10.1038/nmat3477]

[3] ELECTROCHEMICAL PHOTOLYSIS OF WATER AT A SEMICONDUCTOR ELECTRODE [J].

FUJISHIMA, A ;

HONDA, K .

NATURE, 1972, 238 (5358) :37-+

[4] LIGHT-INDUCED REDOX REACTIONS IN NANOCRYSTALLINE SYSTEMS [J].

HAGFELDT, A ;

GRATZEL, M .

CHEMICAL REVIEWS, 1995, 95 (01) :49-68

[5] New benchmark for water photooxidation by nanostructured α-Fe2O3 films [J].

Kay, Andreas ;

Cesar, Ilkay ;

Graetzel, Michael .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2006, 128 (49) :15714-15721

[6] INFLUENCE OF ANTIFERROMAGNETIC FE3+-O-CR3+ INTERACTIONS ON THE OPTICAL-SPECTRUM IN OXIDES OF CORUNDUM AND SPINEL-TYPE [J].

LENGLET, M ;

HOCHU, F ;

MUSIC, S .

SOLID STATE COMMUNICATIONS, 1995, 94 (03) :211-215

[7] Epitaxial Structures of Band-Gap-Engineered α-(CrxFe1-x)2O3 (0 ≤ x ≤ 1) Films Grown on C-Plane Sapphire [J].

Mashiko, Hisanori ;

Oshima, Takayoshi ;

Ohtomo, Akira .

JAPANESE JOURNAL OF APPLIED PHYSICS, 2012, 51 (11)

[8] Band-gap narrowing in α-(CrxFe1-x)2O3 solid-solution films [J].

Mashiko, Hisanori ;

Oshima, Takayoshi ;

Ohtomo, Akira .

APPLIED PHYSICS LETTERS, 2011, 99 (24)

[9] The application of TiO2 photocatalysis for disinfection of water contaminated with pathogenic micro-organisms:: a review [J].

McCullagh, Cathy ;

Robertson, Jeanette M. C. ;

Bahnemann, Detlef W. ;

Robertson, Peter K. J. .

RESEARCH ON CHEMICAL INTERMEDIATES, 2007, 33 (3-5) :359-375

[10] First-principles study of the mixed oxide α-FeCrO3 [J].

Moore, Elaine A. .

PHYSICAL REVIEW B, 2007, 76 (19)

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