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Hexagonal nanoporous germanium through surfactant-driven self-assembly of Zintl clusters

Authors: Dong Sun, Andrew E. Riley, Ashley Cadby, Erik K. Richman, Scott D. Korlann, Sarah H. Tolbert

Date: September 2015

Type: Journal article, Nature, 441(7097)

Download a PDF version of the paper from Nature

Abstract:

Surfactant templating is a method that has successfully been used to produce nanoporous inorganic structures from a wide range of oxide-based material.

Co-assembly of inorganic precursor molecules with amphiphilic organic molecules is followed first by inorganic condensation to produce rigid amorphous frameworks and then, by template removal, to produce mesoporous solids.

A range of periodic surfactant/semiconductor and surfactant/metal composites have also been produced by similar methods but for virtually all the non-oxide semiconducting phases, the surfactant unfortunately cannot be removed to generate porous materials.

Here we show that it is possible to use surfactant-driven self-organisation of soluble Zintl clusters to produce periodic, nanoporous versions of classic semiconductors such as amorphous Ge or Ge/Si alloys. Specifically, we use derivatives of the anionic Ge94- cluster, a compound whose use in the synthesis of nanoscale materials is established. Moreover, because of the small size, high surface area, and flexible chemistry of these materials, we can tune optical properties in these nanoporous semiconductors through quantum confinement by adsorption of surface species, or by altering the elemental composition of the inorganic framework.

Because the semiconductor surface is exposed and accessible in these materials, they have the potential to interact with a range of species in ways that could eventually lead to new types of sensors or other novel nanostructured devices.

Citation information

@article{cite-key,

Abstract = {`Porous'silicon was hailed as an exciting new material for microelectronics when it was first produced 15 years ago. It provided an alternative range of properties to complement those of crystalline silicon. Now germanium, another element important in microelectronics, has come under scrutiny, and two groups report the use of a technique called surfactant templating to synthesize germanium with ordered pores: one group obtains cubic, and the other, hexagonal geometry. Initial investigations show that, as with porous silicon, these materials also have differing properties to their bulk counterparts.},

Author = {Sun, Dong and Riley, Andrew E. and Cadby, Ashley J. and Richman, Erik K. and Korlann, Scott D. and Tolbert, Sarah H.},

Da = {2006/06/01},

Date-Added = {2019-08-21 22:25:27 +0000},

Date-Modified = {2019-08-21 22:25:27 +0000},

Doi = {10.1038/nature04891},

Id = {Sun2006},

Isbn = {1476-4687},

Journal = {Nature},

Number = {7097},

Pages = {1126--1130},

Title = {Hexagonal nanoporous germanium through surfactant-driven self-assembly of Zintl clusters},

Ty = {JOUR},

Url = {https://doi.org/10.1038/nature04891},

Volume = {441},

Year = {2006},

Bdsk-Url-1 = {https://doi.org/10.1038/nature04891}}

Recent publications

A multimodal adaptive super-resolution and confocal microscope

Author: Ashley Cadby

Date: April 2019

Type: Preprint

Read the paper online

Abstract:

Existing optical microscopy techniques compromise between resolution, photodamage, speed of acquisition and imaging in to deep samples. This often confines a technique to a certain biological system or process.

We present a versatile imaging system which can switch between imaging modalities with sub millisecond transition times to adapt to the needs of a wide range of sample types. The imaging modalities provide the minimally invasive but low-resolution epi-fluorescence though increasing invasive but higher resolution confocal and structured illumination until the highest resolution is achieved through the most intrusive, localisation microscopy. The ability of the system to overcome the limitations of conventional single mode microscopy is demonstrated by several biological investigations.

The ideas presented in this work allow researchers to move away from the model of a single imaging modality to study a specific process and instead follow those processes using the most suitable method available during the lifetime of the investigation.

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