Growth of gold tips onto hyperbranched CdTe nanostructures

Yuriy Khalavka ,  Carsten Sönnichsen 

Johannes Gutenberg Universität, Institut für Physikalische Chemie, Jakob Welder Weg, 11, Mainz 55128, Germany

Abstract

The creation of hybrid metal-semiconductor nanostructures is an important next step towards active devises from inorganic nanocrystals. There is also considerable interplay between the optical and electronic behavior of the components of such hybrid materials, potentially leading to enhanced or new properties. The gold tipped hyperbranched particles provide not only an significant progress in the level of control over inorganic hybrid nano-materials but may allow creating blends with organic molecules for novel electronic and optical materials.

Here we report the synthesis of a novel type of metal-semiconductor hybrid materials based on CdTe hyperbranched particles. Gold particles were grown selectively onto the tips of preformed semiconductor substrates at room temperature under open-air condition. The kinetic balance seems to be critical, which is also evident from experiments in different solvents.We use the method of TEM tomography, where the 3-dimensional particle shape is reconstructed from a tilt series of TEM images. We observed a significant flattening of the three-dimensional structure of the hyperbranched particles after reaction with the gold solution and deposition on the TEM grids.

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Figure 1. TEM image showing growth of gold onto the tips of CdTe hyperbranched particles.

We have prepared a novel type of hybrid metal-semiconductor Au-CdTe nanostructures with very complex shapes, enormously large surface to volume ratio and well defined evenly sized gold anchor points at the tips. It may give rise to a new class of multifunctional materials, in particular in combination with organic molecules, with possible application for example in energy conversion devices, bio-functionalized materials, and infrared emitting/detecting devices.

 

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Presentation: Oral at E-MRS Fall Meeting 2007, Acta Materialia Gold Medal Workshop, by Yuriy Khalavka
See On-line Journal of E-MRS Fall Meeting 2007

Submitted: 2007-05-08 11:53
Revised:   2009-06-07 00:44