PHOTOELECTROCHEMICAL PRODUCTION of HYDROGEN

In this year’s Phase II photoelectrochemical hydrogen production research at the University of Hawaii, we have continued our emphasis on developing high-performance multi-junction hydrogen photoelectrodes based on low cost semiconductor and catalyst films. Significant progress was made in the advancement of amorphous silicon/germanium and copper indium gallium diselenide materials for solid-state photojunctions, and great strides were made in the research and development of the ‘hybrid’ photoelectrode concept, including important initial work on nanostructured wide-bandgap semiconductor films for the photoelectrochemical interface, particularly iron oxide. A new partnership was established with Duquesne University to take advantage of their demonstrated capabilities in fabrication of nanostructured films of photoactive Fe2O3 deposited by the spray-pyrolysis method; At the same time, an in-house investigation was initiated into the photoelectrochemical properties of reactively-sputtered iron oxide films. The Phase II work of this project is progressing on-schedule: To date, initial sets of prototype hybrid devices based on tandem amorphous silicon/germanium coated with corrosionresistant ITO and non-photoactive Fe2O3 films (sputtered at UH) have been made, and prototypes using photoactive (deposited at Duquesne University) are currently under fabrication. Stable hydrogen photo-production was demonstrated in the hybrid prototypes fabricated with the sputtered iron oxide, but a voltage bias assist of 1V was necessary. Near term plans include testing of the initial set of devices being fabricated with Duquesne’s photo-active films for unassisted photo-production. We plan to follow analysis of the test results by a redesign of a second generation prototype with optimized interface and optical properties, for fabrication and testing by the end of the contract period. 1 Proceedings of the 2002 U.S. DOE Hydrogen Program Review NREL/CP-610-32405