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Title: Microstructure of Amorphous-Silicon-Based Solar Cell Materials by Small-Angle X-Ray Scattering; Final Subcontract Report: 6 April 1994 - 30 June 1998

Abstract

This report describes work performed to provide details of the microstructure in high-quality hydrogenated amorphous silicon and related alloys for the nanometer size scale. The materials studied were prepared by current state-of-the-art deposition methods, as well as new and emerging deposition techniques. The purpose was to establish the role of microstructural features in controlling the opto-electronic and photovoltaic properties. The approach centered around the use of the uncommon technique of small-angle X-ray scattering (SAXS), which is highly sensitive to microvoids and columnar-like microstructure. Nanovoids of H-rich clusters with 1 to 4 nm sizes in a-Si:H at the 1 vol.% level correlate with poor solar-cell and opto-electronic behavior. Larger-scale features due either to surface roughness or residual columnar-like structures were found in present state-of-the-art device material. Ge alloying above about 10 to 20 at.% typically leads to significant increases in heterogeneity , and this has been shown to be due in part to non-uniform Ge distributions. Ge additions also cause columnar-like growth, but this can be reduced or eliminated by enhanced ion bombardment during growth. In contrast, C alloying typically induces a random nanostructure consisting of a narrow size distribution of 1-nm-sized objects with a high density, consistent with the notablymore » poorer opto-electronic behavior of these alloys.« less

Authors:
 [1]
  1. (Department of Physics: Colorado School of Mines)
Publication Date:
Research Org.:
National Renewable Energy Lab., Golden, CO (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
14403
Report Number(s):
NREL/SR-520-25844
TRN: US200311%%2
DOE Contract Number:  
AC36-83CH10093
Resource Type:
Technical Report
Resource Relation:
Other Information: Supercedes report DE00014403; PBD: 8 Dec 1998; PBD: 8 Dec 1998
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; MICROSTRUCTURE; ROUGHNESS; SMALL ANGLE SCATTERING; SILICON SOLAR CELLS; X-RAY DIFFRACTION; AMORPHOUS STATE; MICROSTRUCTURES; PHOTOVOLTAICS; AMORPHOUS-SILICON MATERIALS; SMALL-ANGLE X-RAY SCATTERING; SAXS; GE ALLOYING

Citation Formats

Williamson, D.L. Microstructure of Amorphous-Silicon-Based Solar Cell Materials by Small-Angle X-Ray Scattering; Final Subcontract Report: 6 April 1994 - 30 June 1998. United States: N. p., 1998. Web. doi:10.2172/14403.
Williamson, D.L. Microstructure of Amorphous-Silicon-Based Solar Cell Materials by Small-Angle X-Ray Scattering; Final Subcontract Report: 6 April 1994 - 30 June 1998. United States. doi:10.2172/14403.
Williamson, D.L. Tue . "Microstructure of Amorphous-Silicon-Based Solar Cell Materials by Small-Angle X-Ray Scattering; Final Subcontract Report: 6 April 1994 - 30 June 1998". United States. doi:10.2172/14403. https://www.osti.gov/servlets/purl/14403.
@article{osti_14403,
title = {Microstructure of Amorphous-Silicon-Based Solar Cell Materials by Small-Angle X-Ray Scattering; Final Subcontract Report: 6 April 1994 - 30 June 1998},
author = {Williamson, D.L.},
abstractNote = {This report describes work performed to provide details of the microstructure in high-quality hydrogenated amorphous silicon and related alloys for the nanometer size scale. The materials studied were prepared by current state-of-the-art deposition methods, as well as new and emerging deposition techniques. The purpose was to establish the role of microstructural features in controlling the opto-electronic and photovoltaic properties. The approach centered around the use of the uncommon technique of small-angle X-ray scattering (SAXS), which is highly sensitive to microvoids and columnar-like microstructure. Nanovoids of H-rich clusters with 1 to 4 nm sizes in a-Si:H at the 1 vol.% level correlate with poor solar-cell and opto-electronic behavior. Larger-scale features due either to surface roughness or residual columnar-like structures were found in present state-of-the-art device material. Ge alloying above about 10 to 20 at.% typically leads to significant increases in heterogeneity , and this has been shown to be due in part to non-uniform Ge distributions. Ge additions also cause columnar-like growth, but this can be reduced or eliminated by enhanced ion bombardment during growth. In contrast, C alloying typically induces a random nanostructure consisting of a narrow size distribution of 1-nm-sized objects with a high density, consistent with the notably poorer opto-electronic behavior of these alloys.},
doi = {10.2172/14403},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Dec 08 00:00:00 EST 1998},
month = {Tue Dec 08 00:00:00 EST 1998}
}

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