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Investigation on the Gap Density of States in Amorphous Semiconducting Carbon Silicon and Carbon Tin Alloys

Published online by Cambridge University Press:  25 February 2011

P. Mpawenayo  and
M. Nsabimana
P. Mpawenayo
Affiliation:
Politecnico di Torino, Dipartimento di Fisica Corso Duca Degli Abruzzi 24, 1019 TORINO (Italy)
M. Nsabimana
Affiliation:
Università di Roma “La Sapienza”, Dipartimento di Fisica Piazzale Aldo Moro 2, 00185 ROMA (Italy)
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Abstract

The density of states in a-Six C1-x:H and a-Cy Sn1-y:H (F) semiconducting materials has been investigated by phototheTmal deflection spectroscopy (PDS) and their photoconductive properties have been related to the gap states distribution parameters, the Urbach energy Eo and the localized states density gm. We found that an Eo of 200 meV is the highest value above which no photoconductivity can be detected. This threshold corresponds to a density of gap states of about 1019 eV−1 cm−3 for optical gaps ranging between 1.1 and 2.5eV. Fourier spectral analysis of the long photoresponse decay time observed in our fluorinated a-Cy, Sn1-y samples shows the existence of well defined trapping levels and randomly distributed defect states.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 97: Symposium I – Novel Refractory Semiconductors , 1987 , 301
Copyright
Copyright © Materials Research Society 1987

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References

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