Abstract
Although II-VI semiconductors such as CdS, CdTe, CdSe, ZnTe, and alloys thereof can have nearly ideal band gaps and band-edge positions for the production of solar fuels, II-VI photoanodes are well-known to be unstable towards photocorrosion or photopassivation when in contact with aqueous electrolytes. Atomic-layer deposition (ALD) of amorphous, "leaky" TiO2 films coated with thin films or islands of Ni oxide has been shown to robustly protect Si, GaAs, and other III-V materials from photocorrosion and therefore to facilitate the robust, solar-driven photoelectrochemical oxidation of H2O to O2(g). We demonstrate herein that ALD-deposited 140 nm thick amorphous TiO2 films also effectively protect single crystalline n-CdTe photoanodes from corrosion or passivation. An n-CdTe/TiO2 electrode with a thin overlayer of a Ni-oxide based oxygen-evolution electrocatalyst produced 435 ± 15 mV of photovoltage with a light-limited current density of 21 ± 1 mA cm-2 under 100 mW cm-2 of simulated Air Mass 1.5 illumination. The ALD-deposited TiO2 films are highly optically transparent and electrically conductive. We show that an n-CdTe/TiO2/Ni oxide electrode enables the stable solar-driven oxidation of H2O to O2(g) in strongly alkaline aqueous solutions, where passive, intrinsically safe, efficient systems for solar-driven water splitting can be operated.
| Original language | English |
|---|---|
| Pages (from-to) | 3334-3337 |
| Number of pages | 4 |
| Journal | Energy and Environmental Science |
| Volume | 7 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 1 2014 |
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ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Environmental Chemistry
- Pollution
- Nuclear Energy and Engineering
Cite this
Stabilization of n-cadmium telluride photoanodes for water oxidation to O2(g) in aqueous alkaline electrolytes using amorphous TiO2 films formed by atomic-layer deposition. / Lichterman, Michael F.; Carim, Azhar I.; McDowell, Matthew T.; Hu, Shu; Gray, Harry B.; Brunschwig, Bruce S.; Lewis, Nathan S.
In: Energy and Environmental Science, Vol. 7, No. 10, 01.10.2014, p. 3334-3337.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Stabilization of n-cadmium telluride photoanodes for water oxidation to O2(g) in aqueous alkaline electrolytes using amorphous TiO2 films formed by atomic-layer deposition
AU - Lichterman, Michael F.
AU - Carim, Azhar I.
AU - McDowell, Matthew T.
AU - Hu, Shu
AU - Gray, Harry B.
AU - Brunschwig, Bruce S.
AU - Lewis, Nathan S
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Although II-VI semiconductors such as CdS, CdTe, CdSe, ZnTe, and alloys thereof can have nearly ideal band gaps and band-edge positions for the production of solar fuels, II-VI photoanodes are well-known to be unstable towards photocorrosion or photopassivation when in contact with aqueous electrolytes. Atomic-layer deposition (ALD) of amorphous, "leaky" TiO2 films coated with thin films or islands of Ni oxide has been shown to robustly protect Si, GaAs, and other III-V materials from photocorrosion and therefore to facilitate the robust, solar-driven photoelectrochemical oxidation of H2O to O2(g). We demonstrate herein that ALD-deposited 140 nm thick amorphous TiO2 films also effectively protect single crystalline n-CdTe photoanodes from corrosion or passivation. An n-CdTe/TiO2 electrode with a thin overlayer of a Ni-oxide based oxygen-evolution electrocatalyst produced 435 ± 15 mV of photovoltage with a light-limited current density of 21 ± 1 mA cm-2 under 100 mW cm-2 of simulated Air Mass 1.5 illumination. The ALD-deposited TiO2 films are highly optically transparent and electrically conductive. We show that an n-CdTe/TiO2/Ni oxide electrode enables the stable solar-driven oxidation of H2O to O2(g) in strongly alkaline aqueous solutions, where passive, intrinsically safe, efficient systems for solar-driven water splitting can be operated.
AB - Although II-VI semiconductors such as CdS, CdTe, CdSe, ZnTe, and alloys thereof can have nearly ideal band gaps and band-edge positions for the production of solar fuels, II-VI photoanodes are well-known to be unstable towards photocorrosion or photopassivation when in contact with aqueous electrolytes. Atomic-layer deposition (ALD) of amorphous, "leaky" TiO2 films coated with thin films or islands of Ni oxide has been shown to robustly protect Si, GaAs, and other III-V materials from photocorrosion and therefore to facilitate the robust, solar-driven photoelectrochemical oxidation of H2O to O2(g). We demonstrate herein that ALD-deposited 140 nm thick amorphous TiO2 films also effectively protect single crystalline n-CdTe photoanodes from corrosion or passivation. An n-CdTe/TiO2 electrode with a thin overlayer of a Ni-oxide based oxygen-evolution electrocatalyst produced 435 ± 15 mV of photovoltage with a light-limited current density of 21 ± 1 mA cm-2 under 100 mW cm-2 of simulated Air Mass 1.5 illumination. The ALD-deposited TiO2 films are highly optically transparent and electrically conductive. We show that an n-CdTe/TiO2/Ni oxide electrode enables the stable solar-driven oxidation of H2O to O2(g) in strongly alkaline aqueous solutions, where passive, intrinsically safe, efficient systems for solar-driven water splitting can be operated.
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U2 - 10.1039/c4ee01914h
DO - 10.1039/c4ee01914h
M3 - Article
VL - 7
SP - 3334
EP - 3337
JO - Energy and Environmental Science
JF - Energy and Environmental Science
SN - 1754-5692
IS - 10
ER -