Abstract
The solar-to-hydrogen (STH) efficiency limits, along with the maximum efficiency values and the corresponding optimal band gap combinations, have been evaluated for various combinations of light absorbers arranged in a tandem configuration in realistic, operational water-splitting prototypes. To perform the evaluation, a current-voltage model was employed, with the light absorbers, electrocatalysts, solution electrolyte, and membranes coupled in series, and with the directions of optical absorption, carrier transport, electron transfer and ionic transport in parallel. The current density vs. voltage characteristics of the light absorbers were determined by detailed-balance calculations that accounted for the Shockley-Queisser limit on the photovoltage of each absorber. The maximum STH efficiency for an integrated photoelectrochemical system was found to be ∼31.1% at 1 Sun (=1 kW m-2, air mass 1.5), fundamentally limited by a matching photocurrent density of 25.3 mA cm-2produced by the light absorbers. Choices of electrocatalysts, as well as the fill factors of the light absorbers and the Ohmic resistance of the solution electrolyte also play key roles in determining the maximum STH efficiency and the corresponding optimal tandem band gap combination. Pairing 1.6-1.8 eV band gap semiconductors with Si in a tandem structure produces promising light absorbers for water splitting, with theoretical STH efficiency limits of >25%.
| Original language | English |
|---|---|
| Pages (from-to) | 2984-2993 |
| Number of pages | 10 |
| Journal | Energy and Environmental Science |
| Volume | 6 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 2013 |
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ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Environmental Chemistry
- Pollution
- Nuclear Energy and Engineering
Cite this
An analysis of the optimal band gaps of light absorbers in integrated tandem photoelectrochemical water-splitting systems. / Hu, Shu; Xiang, Chengxiang; Haussener, Sophia; Berger, Alan D.; Lewis, Nathan S.
In: Energy and Environmental Science, Vol. 6, No. 10, 2013, p. 2984-2993.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An analysis of the optimal band gaps of light absorbers in integrated tandem photoelectrochemical water-splitting systems
AU - Hu, Shu
AU - Xiang, Chengxiang
AU - Haussener, Sophia
AU - Berger, Alan D.
AU - Lewis, Nathan S
PY - 2013
Y1 - 2013
N2 - The solar-to-hydrogen (STH) efficiency limits, along with the maximum efficiency values and the corresponding optimal band gap combinations, have been evaluated for various combinations of light absorbers arranged in a tandem configuration in realistic, operational water-splitting prototypes. To perform the evaluation, a current-voltage model was employed, with the light absorbers, electrocatalysts, solution electrolyte, and membranes coupled in series, and with the directions of optical absorption, carrier transport, electron transfer and ionic transport in parallel. The current density vs. voltage characteristics of the light absorbers were determined by detailed-balance calculations that accounted for the Shockley-Queisser limit on the photovoltage of each absorber. The maximum STH efficiency for an integrated photoelectrochemical system was found to be ∼31.1% at 1 Sun (=1 kW m-2, air mass 1.5), fundamentally limited by a matching photocurrent density of 25.3 mA cm-2produced by the light absorbers. Choices of electrocatalysts, as well as the fill factors of the light absorbers and the Ohmic resistance of the solution electrolyte also play key roles in determining the maximum STH efficiency and the corresponding optimal tandem band gap combination. Pairing 1.6-1.8 eV band gap semiconductors with Si in a tandem structure produces promising light absorbers for water splitting, with theoretical STH efficiency limits of >25%.
AB - The solar-to-hydrogen (STH) efficiency limits, along with the maximum efficiency values and the corresponding optimal band gap combinations, have been evaluated for various combinations of light absorbers arranged in a tandem configuration in realistic, operational water-splitting prototypes. To perform the evaluation, a current-voltage model was employed, with the light absorbers, electrocatalysts, solution electrolyte, and membranes coupled in series, and with the directions of optical absorption, carrier transport, electron transfer and ionic transport in parallel. The current density vs. voltage characteristics of the light absorbers were determined by detailed-balance calculations that accounted for the Shockley-Queisser limit on the photovoltage of each absorber. The maximum STH efficiency for an integrated photoelectrochemical system was found to be ∼31.1% at 1 Sun (=1 kW m-2, air mass 1.5), fundamentally limited by a matching photocurrent density of 25.3 mA cm-2produced by the light absorbers. Choices of electrocatalysts, as well as the fill factors of the light absorbers and the Ohmic resistance of the solution electrolyte also play key roles in determining the maximum STH efficiency and the corresponding optimal tandem band gap combination. Pairing 1.6-1.8 eV band gap semiconductors with Si in a tandem structure produces promising light absorbers for water splitting, with theoretical STH efficiency limits of >25%.
UR - http://www.scopus.com/inward/record.url?scp=84883669048&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84883669048&partnerID=8YFLogxK
U2 - 10.1039/c3ee40453f
DO - 10.1039/c3ee40453f
M3 - Article
AN - SCOPUS:84883669048
VL - 6
SP - 2984
EP - 2993
JO - Energy and Environmental Science
JF - Energy and Environmental Science
SN - 1754-5692
IS - 10
ER -