Modeling of Optical and Electrical Losses in Photoelectrochemical Cells
a Institute of Computational Physics, Zurich University of Applied Sciences, Wildbachstrasse, 21, Winterthur, Switzerland
Proceedings of International Conference on New Advances in Materials Research for Solar Fuels Production (SolarFuel14)
Montréal, Canada, 2014 June 25th - 26th
Organizer: Thomas Hamann
Oral, Peter Cendula, presentation 008
Publication date: 16th April 2014
Publication date: 16th April 2014
We developed an experimentally validated optical model of a photoelectrochemical (PEC) cell. Optical losses contribute substantially to the overall solar-to-hydrogen energy conversion losses. Since a PEC cell consists of a number of layers with different optical properties, each of the layers needs to be properly included in the optical model. Layers thicker than the wavelength of light are modeled as incoherent layers and ray-tracing is used to follow multiple reflections of the incident light. Layers with thickness comparable to the wavelength of light are treated as coherent layers and modeled using a transfer-matrix formalism. Based on our optical model, spectral transmittance, reflectance, and absorptance losses can be quantified.
Our electrical model of a semiconductor PEC electrode was extended to account for the potential drop in the Helmholtz layer [1,2]. Band edge pinning and unpinning are then naturally included in our description. The model is based on the continuity equations for charge carriers and direct charge transfer from the energy bands to the electrolyte. The current-voltage curve and impedance response of a PEC electrode is calculated from the electrical model and compared with measurements. This enables the detailed model-based analysis of PEC electrodes.
[1] J. Bisquert et al., J. Phys. Chem. Lett. 5, 205-207 (2014).
[2] P. Cendula et al., submitted (2014).
Our electrical model of a semiconductor PEC electrode was extended to account for the potential drop in the Helmholtz layer [1,2]. Band edge pinning and unpinning are then naturally included in our description. The model is based on the continuity equations for charge carriers and direct charge transfer from the energy bands to the electrolyte. The current-voltage curve and impedance response of a PEC electrode is calculated from the electrical model and compared with measurements. This enables the detailed model-based analysis of PEC electrodes.
[1] J. Bisquert et al., J. Phys. Chem. Lett. 5, 205-207 (2014).
[2] P. Cendula et al., submitted (2014).
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