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Title: Characterization and control of crystal nucleation in amorphous electron beam evaporated silicon for thin film solar cells

Abstract

The kinetics of crystal nucleation in high-rate electron beam evaporated amorphous Si for polycrystalline thin film solar cells was systematically studied on SiN and selected ZnO:Al-coated glass substrates with dissimilar surface topographies by employing Raman spectroscopy, transmission electron microscopy, and optical microscopy. The influence of the surface topography of the substrate and the disorder of the deposited amorphous Si could be correlated to the respective characteristics of the transient and steady state regime of the nucleation rate. The steady state nucleation rate I{sub ss}, its corresponding activation energy E{sub Iss}, and consequently the size of the grains in the crystallized Si were found to be governed by the interplay between the surface roughness and the deposition temperature. The steady state nucleation rate I{sub ss} increased gradually upon increasing the substrate roughness, while lowering the deposition temperature of the amorphous Si on rough textures resulted in a decline of I{sub ss}. The time-lag {tau}, which represents a distinctive parameter for the transient regime, was only slightly affected by the substrate topography. The deposition temperature, however, had a significant influence on {tau}, with {tau} increasing by a factor of 8 upon lowering the deposition temperature from 300 to 200 deg. C formore » all substrate topographies. These characteristics could be correlated with the increasing structural disorder of the deposited a-Si upon decreasing the deposition temperature. Based on this analysis, we could determine design rules for the controlled preparation of large-grained poly-Si in minimized processing time on any of the used substrate types by individually adjusting the deposition temperature and implementing nucleation layers.« less

Authors:
; ; ; ;  [1]
  1. Helmholtz Zentrum Berlin fuer Materialien und Energie, Institute Silicon Photovoltaics, Kekulestr. 5, 12489 Berlin (Germany)
Publication Date:
OSTI Identifier:
22038708
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 110; Journal Issue: 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; AMORPHOUS STATE; DEPOSITION; ELECTRON BEAMS; GRAIN SIZE; NUCLEATION; OPTICAL MICROSCOPY; POLYCRYSTALS; RAMAN SPECTROSCOPY; SEMICONDUCTOR MATERIALS; SILICON; SILICON NITRIDES; SOLAR CELLS; STEADY-STATE CONDITIONS; SUBSTRATES; TEXTURE; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; ZINC OXIDES

Citation Formats

Sontheimer, Tobias, Scherf, Simone, Klimm, Carola, Becker, Christiane, and Rech, Bernd. Characterization and control of crystal nucleation in amorphous electron beam evaporated silicon for thin film solar cells. United States: N. p., 2011. Web. doi:10.1063/1.3627373.
Sontheimer, Tobias, Scherf, Simone, Klimm, Carola, Becker, Christiane, & Rech, Bernd. Characterization and control of crystal nucleation in amorphous electron beam evaporated silicon for thin film solar cells. United States. doi:10.1063/1.3627373.
Sontheimer, Tobias, Scherf, Simone, Klimm, Carola, Becker, Christiane, and Rech, Bernd. Thu . "Characterization and control of crystal nucleation in amorphous electron beam evaporated silicon for thin film solar cells". United States. doi:10.1063/1.3627373.
@article{osti_22038708,
title = {Characterization and control of crystal nucleation in amorphous electron beam evaporated silicon for thin film solar cells},
author = {Sontheimer, Tobias and Scherf, Simone and Klimm, Carola and Becker, Christiane and Rech, Bernd},
abstractNote = {The kinetics of crystal nucleation in high-rate electron beam evaporated amorphous Si for polycrystalline thin film solar cells was systematically studied on SiN and selected ZnO:Al-coated glass substrates with dissimilar surface topographies by employing Raman spectroscopy, transmission electron microscopy, and optical microscopy. The influence of the surface topography of the substrate and the disorder of the deposited amorphous Si could be correlated to the respective characteristics of the transient and steady state regime of the nucleation rate. The steady state nucleation rate I{sub ss}, its corresponding activation energy E{sub Iss}, and consequently the size of the grains in the crystallized Si were found to be governed by the interplay between the surface roughness and the deposition temperature. The steady state nucleation rate I{sub ss} increased gradually upon increasing the substrate roughness, while lowering the deposition temperature of the amorphous Si on rough textures resulted in a decline of I{sub ss}. The time-lag {tau}, which represents a distinctive parameter for the transient regime, was only slightly affected by the substrate topography. The deposition temperature, however, had a significant influence on {tau}, with {tau} increasing by a factor of 8 upon lowering the deposition temperature from 300 to 200 deg. C for all substrate topographies. These characteristics could be correlated with the increasing structural disorder of the deposited a-Si upon decreasing the deposition temperature. Based on this analysis, we could determine design rules for the controlled preparation of large-grained poly-Si in minimized processing time on any of the used substrate types by individually adjusting the deposition temperature and implementing nucleation layers.},
doi = {10.1063/1.3627373},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 6,
volume = 110,
place = {United States},
year = {2011},
month = {9}
}