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Quantification of Nanoscale Density Fluctuations in Hydrogenated Amorphous Silicon
- Source :
- Physical Review Letters, 125(18):185501. American Physical Society
- Publication Year :
- 2020
-
Abstract
- The nanostructure of hydrogenated amorphous silicon (a Si:H) is studied by a combination of small-angle X-ray (SAXS) and neutron scattering (SANS) with a spatial resolution of 0.8 nm. The a-Si:H materials were deposited using a range of widely varied conditions and are representative for this class of materials. We identify two different phases which are embedded in the a-Si:H matrix and quantified both according to their scattering cross-sections. First, 1.2 nm sized voids (multivacancies with more than 10 missing atoms) which form a superlattice with 1.6 nm void-to-void distance are detected. The voids are found in concentrations as high as 6*10^19 ccm in a-Si:H material that is deposited at a high rate. Second, dense ordered domains (DOD) that are depleted of hydrogen with 1 nm average diameter are found. The DOD tend to form 10-15 nm sized aggregates and are largely found in all a-Si:H materials considered here. These quantitative findings make it possible to understand the complex correlation between structure and electronic properties of a-Si:H and directly link them to the light-induced formation of defects. Finally, a structural model is derived, which verifies theoretical predictions about the nanostructure of a-Si:H.<br />Comment: Letter presenting a model for a-Si:H derived by SAXS and SANS
- Subjects :
- Amorphous silicon
Materials science
Nanostructure
Hydrogen
Superlattice
Small angle neutron scattering
Analytical chemistry
General Physics and Astronomy
chemistry.chemical_element
FOS: Physical sciences
Neutron scattering
01 natural sciences
chemistry.chemical_compound
Networks & random structures
0103 physical sciences
010306 general physics
Small-angle x-ray scattering
Condensed Matter - Materials Science
500 Naturwissenschaften und Mathematik::530 Physik::539 Moderne Physik
Scattering
Small-angle X-ray scattering
Materials Science (cond-mat.mtrl-sci)
Amorphous semiconductors
Small-angle neutron scattering
Disordered systems
chemistry
Transmission electron microscopy
Subjects
Details
- Language :
- English
- ISSN :
- 00319007
- Database :
- OpenAIRE
- Journal :
- Physical Review Letters, 125(18):185501. American Physical Society
- Accession number :
- edsair.doi.dedup.....d8f246780b04f5f6f1891fdb6c9c464e