Studying Semiconductor Nanowire Formation with In-Situ TEM

A scientific paper has been published describing how in-situ TEM has been used to study semiconductor nanowire formation at atomic resolution.

The paper was published in PRL (Physical Review Letters) by researchers at the Centre de Nanosciences et de Nanotechnologies (CNRS). The research uses an ETEM and the Protochips Fusion in-situ system.

Blue Scientific is the official distributor for Protochips in the UK, Ireland and Nordic region. If you have any questions or if you’d like a quote, please get in touch:

Protochips Fusion

Article on Physical Review Letters

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Studying Semiconductor Nanowire Formation with In-Situ TEM

Ground-breaking, atomic resolution images of semiconductor nanowire formation at 400ºC have been published in PRL by a researchers at CNRS in Paris.

The authors are Jean-Christophe Harmand, Gilles Patriarche, Frank Glas, Federico Panciera, Ileana Florea, Jean-Luc Maurice, Laurent Travers and Yannick Ollivier.

The publication shows the growth of a semiconductor nanowire at 400ºC from a liquid catalyst, which was imaged using an ETEM (Environmental Transmission Electron Microscope) and the Protochips Fusion in-situ system.

The paper entitled “Atomic Step Flow on a Nanofacet” is available on PRL (subscription required).

Nanowire Growth

Understanding Crystal Growth

The growth of crystals often involves atomic step flow. The nucleation and progression of the steps can be influenced by limiting the surface area – particularly in the growth of nanocrystals.

In the paper, the research team at CNRS studied Au-catalysed GaAs nanowires, grown inside a TEM. By observing them in-situ, they found that the atomic layers nucleate at the edge of the interface between the nanowire and the catalyst droplet.

From this point, the atomic step flows within the restricted, hexagonal shaped area. At particular points along the way, there are noticeable changes in monolayer configuration. This can be defined by a simple model based on the geometry of the system and its associated edge energies.

In particular, there is an inversion of the step curvature. This shows that the effective energy per unit length of monolayer edge is significantly lower at the interface periphery than inside the catalyst droplet. These insights are particularly important because improve our understanding of the crystallisation process in general.

Read the full paper on PRL 

Video

The video below, taken by the team at CNRS, shows a cross-section view of a gallium arsenide nanocrystal growing beneath a droplet of gold supersaturated with gallium and arsenic.

 

Protochips Fusion

The study uses the Protochips Fusion, an in-situ system compatible with TEM / SEM microscopes from all major manufacturers. With the Fusion you can observe the behaviour of samples at precisely controlled temperatures and/or under electrical biasing:

In-Situ Heating

  • Heating up to 1200°C
  • >99.5% temperature uniformity
  • 56x more uniform than coil heating
  • Minimal displacement and drift
  • Up to 1000°C/ms heating/cooling rate

In-Situ Electrical

  • Characterise nanoscale samples with low currents
  • Precise, single digit picoamp measurements
  • Attoamp sensitivity
  • Over 30 sample supports for different applications

More about the Protochips Fusion

Protochips Fusion for electron microscopes

Protochips Fusion in situ system

The Protochips range also includes in-situ systems for liquid microscopy and environmental gas at high pressures and temperatures:

Protochips Poseidon Select

Protochips Poseidon Select liquid microscopy system – more info…

Protochips Atmosphere Environmental Gas In-Situ System

Protochips Atmosphere environmental gas in-situ system – more info…

Further Information

If you’d like to know more about the Protochips Fusion or any of their other systems, please get in touch. Blue Scientific is the official distributor for Protochips in the UK, Ireland and Nordic region. We’re available to provide quotes and answer all your questions:

 Contact us on 01223 422 269 or info@blue-scientific.com

Protochips Fusion

Scientific paper on Physical Review Letters