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Surface Chemistry, Structure, and Electronic Properties from Microns to the Atomic Scale of Axially Doped Semiconductor Nanowires.

Hjort, Martin LU ; Wallentin, Jesper LU ; Timm, Rainer LU ; Zakharov, Alexei LU ; Håkanson, Ulf LU ; Andersen, Jesper N LU ; Lundgren, Edvin LU ; Samuelson, Lars LU ; Borgström, Magnus LU and Mikkelsen, Anders LU (2012) In ACS Nano
Abstract
Using both synchrotron-based photoemission electron microscopy/spectroscopy and scanning tunneling microscopy/spectroscopy, we obtain a complete picture of the surface composition, morphology, and electronic structure of InP nanowires. Characterization is done at all relevant length scales from micrometer to nanometer. We investigate nanowire surfaces with native oxide and molecular adsorbates resulting from exposure to ambient air. Atomic hydrogen exposure at elevated temperatures which leads to the removal of surface oxides while leaving the crystalline part of the wire intact was also studied. We show how surface chemical composition will seriously influence nanowire electronic properties. However, opposite to, for example, Ge... (More)
Using both synchrotron-based photoemission electron microscopy/spectroscopy and scanning tunneling microscopy/spectroscopy, we obtain a complete picture of the surface composition, morphology, and electronic structure of InP nanowires. Characterization is done at all relevant length scales from micrometer to nanometer. We investigate nanowire surfaces with native oxide and molecular adsorbates resulting from exposure to ambient air. Atomic hydrogen exposure at elevated temperatures which leads to the removal of surface oxides while leaving the crystalline part of the wire intact was also studied. We show how surface chemical composition will seriously influence nanowire electronic properties. However, opposite to, for example, Ge nanowires, water or sulfur molecules adsorbed on the exterior oxidized surfaces are of less relevance. Instead, it is the final few atomic layers of the oxide which plays the most significant role by strongly negatively doping the surface. The InP nanowires in air are rather insensitive to their chemical surroundings in contrast to what is often assumed for nanowires. Our measurements allow us to draw a complete energy diagram depicting both band gap and differences in electron affinity across an axial nanowire p-n junction. Our findings thus give a robust set of quantitative values relating surface chemical composition to specific electronic properties highly relevant for simulating the performance of nanoscale devices. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
ACS Nano
publisher
The American Chemical Society
external identifiers
  • wos:000311521700037
  • pmid:23062066
  • scopus:84870410287
ISSN
1936-086X
DOI
10.1021/nn303107g
language
English
LU publication?
yes
id
20d4e6ab-67de-4b74-b92a-3de2d19a5e4c (old id 3160779)
date added to LUP
2012-11-02 14:05:33
date last changed
2017-11-19 03:15:36
@article{20d4e6ab-67de-4b74-b92a-3de2d19a5e4c,
  abstract     = {Using both synchrotron-based photoemission electron microscopy/spectroscopy and scanning tunneling microscopy/spectroscopy, we obtain a complete picture of the surface composition, morphology, and electronic structure of InP nanowires. Characterization is done at all relevant length scales from micrometer to nanometer. We investigate nanowire surfaces with native oxide and molecular adsorbates resulting from exposure to ambient air. Atomic hydrogen exposure at elevated temperatures which leads to the removal of surface oxides while leaving the crystalline part of the wire intact was also studied. We show how surface chemical composition will seriously influence nanowire electronic properties. However, opposite to, for example, Ge nanowires, water or sulfur molecules adsorbed on the exterior oxidized surfaces are of less relevance. Instead, it is the final few atomic layers of the oxide which plays the most significant role by strongly negatively doping the surface. The InP nanowires in air are rather insensitive to their chemical surroundings in contrast to what is often assumed for nanowires. Our measurements allow us to draw a complete energy diagram depicting both band gap and differences in electron affinity across an axial nanowire p-n junction. Our findings thus give a robust set of quantitative values relating surface chemical composition to specific electronic properties highly relevant for simulating the performance of nanoscale devices.},
  author       = {Hjort, Martin and Wallentin, Jesper and Timm, Rainer and Zakharov, Alexei and Håkanson, Ulf and Andersen, Jesper N and Lundgren, Edvin and Samuelson, Lars and Borgström, Magnus and Mikkelsen, Anders},
  issn         = {1936-086X},
  language     = {eng},
  publisher    = {The American Chemical Society},
  series       = {ACS Nano},
  title        = {Surface Chemistry, Structure, and Electronic Properties from Microns to the Atomic Scale of Axially Doped Semiconductor Nanowires.},
  url          = {http://dx.doi.org/10.1021/nn303107g},
  year         = {2012},
}