Electronic and Structural Differences between Wurtzite and Zinc Blende InAs Nanowire Surfaces: Experiment and Theory

Summary, in English

We determine the detailed differences in geometry and band structure between wurtzite (Wz) and zinc blende (Zb) InAs nanowire (NW) surfaces using scanning tunneling microscopy/spectroscopy and photoemission electron microscopy. By establishing unreconstructed and defect-free surface facets for both Wz and Zb, we can reliably measure differences between valence and conduction band edges, the local vacuum levels, and geometric relaxations to the few-millielectronvolt and few-picometer levels, respectively. Surface and bulk density functional theory calculations agree well with the experimental findings and are used to interpret the results, allowing us to obtain information on both surface and bulk electronic structure. We can thus exclude several previously proposed explanations for the observed differences in conductivity of Wz-Zb NW devices. Instead, fundamental structural differences at the atomic scale and nanoscale that we observed between NW surface facets can explain the device behavior.

• Författare: Martin Hjort; Sebastian Lehmann; Johan Knutsson; Alexei Zakharov; Yaojun A. Du; Sung Sakong; Rainer Timm; Gustav Nylund; Edvin Lundgren; Peter Kratzer; Kimberly Dick Thelander; Anders Mikkelsen
• Avdelning/ar: Synkrotronljusfysik; Fasta tillståndets fysik; MAX IV-laboratoriet; NanoLund: Centre for Nanoscience
• Publiceringsår: 2014
• Språk: Engelska
• Sidor: 12346-12355
• Publikation/Tidskrift/Serie: ACS Nano
• Volym: 8
• Issue: 12
• Länkar: http://dx.doi.org/10.1021/nn504795v
• Dokumenttyp: Artikel i tidskrift
• Förlag: The American Chemical Society (ACS)
• Ämne: Nano Technology
• Nyckelord: STM; InAs nanowire; surface; STS; PEEM; wurtzite
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1936-086X