| Autor: |
Cordoba, Cristina, Zeng, Xulu, Wolf, Daniel, Lubk, Axel, Barrigón, Enrique, Borgström, Magnus T., Kavanagh, Karen L. |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Nano Lett. 2019, 19, 6, 3490-3497 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1021/acs.nanolett.9b00249 |
| Popis: |
Electron Holographic Tomography was used to obtain 3-dimensional reconstructions of the morphology and electrostatic potential gradient of axial GaInP/InP nanowire tunnel diodes. Crystal growth was carried out in two opposite directions: GaInP:Zn/InP:S and InP:Sn/GaInP:Zn, using Zn as the p-type dopant in the GaInP, but with changes to the n-type dopant (S or Sn) in the InP. Secondary electron and electron beam induced current images obtained using scanning electron microscopy indicated the presence of p-n junctions in both cases and current-voltage characteristics measured via lithographic contacts showed the negative differential resistance, characteristic of band-to-band tunneling, for both diodes. EHT measurements confirmed a short depletion width in both cases ($21 \pm 3$ nm), but different built-in potentials, $V_{bi}$, of 1.0 V for the p-type (Zn) to n-type (S) transition, and 0.4 V for both were lower than the expected 1.5 V for these junctions, if degenerately-doped. Charging induced by the electron beam was evident in phase images which showed non-linearity in the surrounding vacuum, most severe in the case of the nanowire grounded at the \emph{p}-type Au contact. We attribute their lower $V_{bi}$ to asymmetric secondary electron emission, beam-induced current biasing and poor grounding contacts. |
| Databáze: |
arXiv |
| Externí odkaz: |
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