Probing Surface Band Bending of Surface-Engineered Metal Oxide Nanowires

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Cheng-Ying Chen
  • Jose Ramon Duran Retamal
  • I-Wen Wu
  • Der-Hsien Lien
  • Ming-Wei Chen
  • Yong Ding
  • Yu-Lun Chueh
  • Chih-I. Wu

Detail(s)

Original languageEnglish
Pages (from-to)9366-9372
Journal / PublicationACS Nano
Volume6
Issue number11
Online published24 Oct 2012
Publication statusPublished - 27 Nov 2012
Externally publishedYes

Abstract

We in situ probed the surface band bending (SBB) by ultraviolet photoelectron spectroscopy (UPS) in conjunction with field-effect transistor measurements on the incompletely depleted ZnO nanowires (NWs). The diameter range of the NWs is ca. 150-350 nm. Several surface treatments (i.e., heat treatments and Au nanoparticle (NP) decoration) were conducted to assess the impact of the oxygen adsorbates on the SBB. A 100 °C heat treatment leads to the decrease of the SBB to 0.74 ± 0.15 eV with 29.9 ± 3.0 nm width, which is attributed to the removal of most adsorbed oxygen molecules from the ZnO NW surfaces. The SBB of the oxygen-adsorbed ZnO NWs is measured to be 1.53 ± 0.15 eV with 43.2 ± 2.0 nm width. The attachment of Au NPs to the NW surface causes unusually high SBB (2.34 ± 0.15 eV with the wide width of 53.3 ± 1.6 nm) by creating open-circuit nano-Schottky junctions and catalytically enhancing the formation of the charge O2 adsorbates. These surface-related phenomena should be generic to all metal oxide nanostructures. Our study is greatly beneficial for the NW-based device design of sensor and optoelectronic applications via surface engineering.

Research Area(s)

  • metal oxide, nanowire, oxygen vacancy, Schottky junction, surface band bending, ZnO

Citation Format(s)

Probing Surface Band Bending of Surface-Engineered Metal Oxide Nanowires. / Chen, Cheng-Ying; Retamal, Jose Ramon Duran; Wu, I-Wen et al.

In: ACS Nano, Vol. 6, No. 11, 27.11.2012, p. 9366-9372.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review