820 mV open-circuit voltages from Cu2O/CH3CN junctions

Chengxiang Xiang, Gregory M. Kimball, Ronald L. Grimm, Bruce S. Brunschwig, Harry A. Atwater, Nathan S. Lewis

Research output: Contribution to journalArticlepeer-review

74 Citations (Scopus)


P-Type cuprous oxide (Cu2O) photoelectrodes prepared by the thermal oxidation of Cu foils exhibited open-circuit voltages in excess of 800 mV in nonaqueous regenerative photoelectrochemical cells. In contact with the decamethylcobaltocene+/0 (Me10CoCp2 +/0) redox couple, cuprous oxide yielded open-circuit voltage, V oc, values of 820 mV and short-circuit current density, J sc, values of 3.1 mA cm-2 under simulated air mass 1.5 illumination. The energy-conversion efficiency of 1.5% was limited by solution absorption and optical reflection losses that reduced the short-circuit photocurrent density. Spectral response measurements demonstrated that the internal quantum yield approached unity in the 400-500 nm spectral range, but poor red response, attributable to bulk recombination, lowered the overall efficiency of the cell. X-Ray photoelectron spectroscopy and Auger electron spectroscopy indicated that the photoelectrodes had a high-quality cuprous oxide surface, and revealed no observable photocorrosion during operation in the nonaqueous electrolyte. The semiconductor/liquid junctions thus provide a noninvasive method to investigate the energy-conversion properties of cuprous oxide without the confounding factors of deleterious surface reactions.

Original languageEnglish
Pages (from-to)1311-1318
Number of pages8
JournalEnergy and Environmental Science
Issue number4
Publication statusPublished - Apr 2011

ASJC Scopus subject areas

  • Environmental Chemistry
  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Pollution

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