High-performance vertical hydrogen sensors using Pd-coated rough Si nanowires

Jin Seo Noh, Hyunsu Kim, Beom Seok Kim, Eunyoung Lee, Hyung Hee Cho, Wooyoung Lee

Research output: Contribution to journalArticlepeer-review

66 Citations (Scopus)


We fabricated Pd-coated rough Si nanowires, using a combination of Si electroless etching and Pd sputtering. The semi-densely distributed, vertical-standing rough Si nanowires, which were clustered locally with inter-cluster distances of several nm to several μm, were selected as a basal platform. Pd was coated only on the upper part of the Si nanowires in the semi-dense configuration, and their surface profile replicated the surface morphology of Si nanowires. The Pd-coated rough Si nanowires showed good reversibility and excellent hydrogen-sensing performance in terms of sensitivity (>300%), response time (<3 s), and detection limit (∼5 ppm). These attributes are discussed in terms of the vertical-standing nanowire structures and the rough surface effect of the nanowires. Interestingly, the variation in sensitivity of the Pd-coated Si nanowire sensors was divided into two regimes, which appeared in the low and high hydrogen concentration ranges, respectively. A simple model is also provided to account for this unusual finding.

Original languageEnglish
Pages (from-to)15935-15939
Number of pages5
JournalJournal of Materials Chemistry
Issue number40
Publication statusPublished - 2011 Oct 28

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Chemistry


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