Patent · US Expired

Stabilization of Si photoanodes in aqueous electrolytes through surface alkylation

US6759349B2 · kind B2 · utility

6Cited by
0References
13Claims
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Key dates

Filing dateMay 4, 1999
Grant dateJul 6, 2004
Priority date
Expiry dateMay 4, 2019

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02E10/542
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A two-step chlorination/alkylation technique used to introduce alkyl groups, —CnH2n+1 (n=1-6), functionally onto single-crystal, (111)-oriented, n-type Si surfaces. H-terminated Si photoanodes were unstable under illumination in contact with an aqueous 0.35 M K4Fe(CN)6-0.05 MK3Fe(CN)6 electrolyte. Such electrodes displayed low open-circuit voltages and exhibited a pronounced time-dependent deterioration in their current density vs potential characteristics due to anodic oxidation. In contrast, Si surfaces functionalized with —CH3 and —C2H5 groups displayed significant improvements in stability while displaying excellent electrochemical properties when used as photoelectrodes in the aqueous Fe(CN)63−/4− electrolyte.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.