Nanoscale Semiconductor/Catalyst Interfaces for Water Splitting Photoanodes
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Date
2019
Authors
Gordon, Adrian Matthew
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
The development of stable and efficient photoanodes for the oxygen evolution reaction (OER) remains a barrier to the realization of commercially viable photoelectrochemical cells. Photoanodes are often fabricated by depositing a thin metal/metal-oxide protection layer on silicon. Studies have shown thinner protection layers correlate with higher performing photoanodes. Additionally repeated electrochemical cycling has shown to enhance performance of photoanodes. Both these phenomena have been hypothesized to result from generation of a spatially inhomogeneous interface following oxidation of the redox active catalyst. The effective barrier height of low barrier height silicon-metal contacts becomes enhanced by surrounding semiconductor-metal oxide contacts, in what is known as the ‘pinch off effect’. In this work, nickel nanoislands which exhibit the pinch off effect are intentionally fabricated using an electrodeposition technique on a silicon photoanode. The efficiency of nanoisland-decorated devices is evaluated using cyclic voltammetry. In addition, we show that electrodeposited contacts can be protected with additional nickel, without compromising their rectifying properties.
Description
35 pages
Keywords
Chemistry, Photoelectrochemical, Cells, Electrochemistry, Solar, Energy