TY - JOUR
T1 - Raman scattering from hydrogenated amorphous silicon
AU - Lyon, S. A.
AU - Nemanich, R. J.
N1 - Funding Information:
In summary, we have observed excess low frequency Raman scattering from a-Si:H. It appears to be very similar to the scattering seen in glasses associated with thermally activated relaxation of TLS. Our data is consistent with the suggestion that 4-fold coordinated materials will have few TLS. When hydrogen is incorporated into the a-Si :it will lower the average coordination number and "open up" the netv~-ork. In addition there is the possibility of TLS involving the motion of hydro- gen. The fact that increasing the hydrogen incorporation enhances the low frequency Raman signal seems to support these conjectures. We would like to thank R.A. Lujan and J.C. Knights for supplying the a-Si:H samples. This work was supported in par t by the Solar Energy Research Institute under contract no. XJ-0-
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1983/3
Y1 - 1983/3
N2 - The Raman scattering from amorphous silicon has been obtained to within 7 cm-1 of the exciting laser line. For hydrogenated silicon the Raman intensity does not go to zero at zero frequency as expected for a Debye solid. Instead, the Raman spectrum is essentially flat for energy shifts below approximately 50 cm-1. Amorphous silicon without hydrogen, produced by ion implantation of arsenic into single crystal silicon, showed at least a factor of 5 less scattering at low energies than heavily hydrogenated films. The temperature dependence of the intensity of the low frequency scattering could not be described by usual one-phonon or two-phonon processes. Similar low frequency scattering has been previously observed from glasses and interpreted in terms of thermally activated relaxation of two-level systems. The data indicate that the incorporation of hydrogen in amorphous silicon produces two-level systems.
AB - The Raman scattering from amorphous silicon has been obtained to within 7 cm-1 of the exciting laser line. For hydrogenated silicon the Raman intensity does not go to zero at zero frequency as expected for a Debye solid. Instead, the Raman spectrum is essentially flat for energy shifts below approximately 50 cm-1. Amorphous silicon without hydrogen, produced by ion implantation of arsenic into single crystal silicon, showed at least a factor of 5 less scattering at low energies than heavily hydrogenated films. The temperature dependence of the intensity of the low frequency scattering could not be described by usual one-phonon or two-phonon processes. Similar low frequency scattering has been previously observed from glasses and interpreted in terms of thermally activated relaxation of two-level systems. The data indicate that the incorporation of hydrogen in amorphous silicon produces two-level systems.
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U2 - 10.1016/0378-4363(83)90679-4
DO - 10.1016/0378-4363(83)90679-4
M3 - Article
AN - SCOPUS:49049126015
SN - 0378-4363
VL - 117-118
SP - 871
EP - 873
JO - Physica B: Physics of Condensed Matter & C: Atomic, Molecular and Plasma Physics, Optics
JF - Physica B: Physics of Condensed Matter & C: Atomic, Molecular and Plasma Physics, Optics
IS - PART 2
ER -