|Posted: Dec 08, 2015|
New probe advances understanding of photoelectrodes(Nanowerk News) Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) have developed a new probe that could lead to a better photoelectrochemical cell.
|A paper on the discovery, 'Semiconductor interfacial carrier dynamics via photoinduced electric fields,' was published in Science Magazine ("Semiconductor interfacial carrier dynamics via photoinduced electric fields").|
|Ye Yang and Jing Gu are lead authors of the paper. NREL colleagues, James Young, Elisa Miller, John Turner, Nathan Neale and Matthew Beard also contributed to the research.|
|Photoelectrochemical cells can be used to convert solar energy into transportable chemical fuels. The photoconversion process employs a semiconductor photoelectrode where photoexcited electrons move to the surface of the electrode to drive chemical reactions, such as reduction of water to produce hydrogen.|
|As the charges move, fields are formed within the photoelectrode. The NREL team developed a spectroscopic probe that for the first time allows the formation and decay of these fields to be monitored directly.|
|The NREL researchers used the new probe to better understand the photophysics of photoelectrodes made from the semiconductor gallium-indium-phosphide (GaInP2). Previous work at NREL used GaInP2 as part of a high-efficiency water splitting system to generate hydrogen from sunlight. By using the newly developed probe, the scientists uncovered the role that a titanium dioxide (TiO2) / GaInP2 interface plays in the photoconversion process.|
|The new measurement tool could lead to improvements in how photoelectrodes are designed to make them more efficient and more stable.|
|Additional research is needed, including the incorporation of a catalyst on the surface of the TiO2, where this technique can be used to understand the role of the catalyst in the hydrogen production reaction.|
|Source: National Renewable Energy Laboratory|
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