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Visualizzazione post con etichetta amorphous matrix. Mostra tutti i post
Visualizzazione post con etichetta amorphous matrix. Mostra tutti i post

lunedì 2 novembre 2020

# gst: density fluctuations may exist in an amorphous matrix

<< Silicon does not have to be crystalline, but can also be produced as an amorphous thin film. In such amorphous films, the atomic structure is disordered like in a liquid or glass. If additional hydrogen is incorporated during the production of these thin layers, so-called a-Si:H layers are formed. >>

<< With this study, we show that the a-Si:H is by no means a homogeneously amorphous material. The amorphous matrix is interspersed with nanometre-sized areas of varying local density, from cavities to areas of extremely high order, >> Klaus Lips

<< We find a nanoscopic order in the disorder of the a-Si:H layers by X-ray scattering measurements (..) We were then able to determine the distribution of the hydrogen atoms in the amorphous network by neutron scattering (..) We were able to discover nanometer-sized voids, which are created by slightly more than 10 missing atoms. These voids arrange themselves into clusters with a recurrent distance of about 1.6 nanometres to each other, >> Eike Gericke

Density fluctuations in amorphous silicon discovered. Helmholtz Association of German Research Centres. Oct 29, 2020. 



Eike Gericke, Jimmy Melskens, et al. Quantification of Nanoscale Density Fluctuations in Hydrogenated Amorphous Silicon. Phys. Rev. Lett. 125, 185501. Oct 29,  2020.