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Title: Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980

Abstract

Despite great theoretical and technological interest in polyacetylene, (CH)/sub x/, the basic features of its band structure have not been unambiguously resolved. Since photoconductivity and optical absorption data have frequently been used to infer information on the band structure of semiconductors, such measurements were carried out on (CH)/sub x/. The main results of an extensive study of the photoconductivity (..delta.. sigma/sub ph/) and absorption coefficient (..cap alpha..) in (CH)/sub x/ are presented. The absence of photoconductivity in cis-(CH)/sub x/, despite the similarity in optical properties indicates that ..delta.. sigma/sub ph/ in trans-(CH)/sub x/ is induced by isomerization. It is found that isomerization generates states deep inside the gap that act as safe traps for minority carriers and thereby enhance the photoconductivity. Compensation of trans-(CH)/sub x/ with ammonia appears to decrease the number of safe traps, whereas acceptor doping increases their number. Thus, chemical doping can be used to control the photoconductive response. The energy of safe traps inside the gap is independent of the process used to generate them; indicative of an intrinsic localized defect level in trans-(CH)/sub x/. A coherent picture based on the soliton model can explain these results, including the safe trapping.

Authors:
;
Publication Date:
Research Org.:
Pennsylvania Univ., Philadelphia (USA)
OSTI Identifier:
5250751
Report Number(s):
DOE/ET/23002-T9
DOE Contract Number:  
AC04-79ET23002
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; ACETYLENE; ABSORPTIVITY; PHOTOCONDUCTIVITY; POLYMERS; SOLAR CELLS; SEMICONDUCTOR MATERIALS; AMMONIA; CRYSTAL DEFECTS; ELECTRIC CONDUCTIVITY; ENERGY GAP; EXPERIMENTAL DATA; GRAPHS; ISOMERIZATION; TRAPS; ALKYNES; CHEMICAL REACTIONS; CRYSTAL STRUCTURE; DATA; DATA FORMS; DIRECT ENERGY CONVERTERS; ELECTRICAL PROPERTIES; EQUIPMENT; HYDRIDES; HYDROCARBONS; HYDROGEN COMPOUNDS; INFORMATION; MATERIALS; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; NUMERICAL DATA; OPTICAL PROPERTIES; ORGANIC COMPOUNDS; PHOTOELECTRIC CELLS; PHOTOVOLTAIC CELLS; PHYSICAL PROPERTIES; SOLAR EQUIPMENT; 140501* - Solar Energy Conversion- Photovoltaic Conversion

Citation Formats

Heeger, A.J., and MacDiarmid, A.G. Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980. United States: N. p., 1980. Web. doi:10.2172/5250751.
Heeger, A.J., & MacDiarmid, A.G. Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980. United States. doi:10.2172/5250751.
Heeger, A.J., and MacDiarmid, A.G. Tue . "Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980". United States. doi:10.2172/5250751. https://www.osti.gov/servlets/purl/5250751.
@article{osti_5250751,
title = {Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980},
author = {Heeger, A.J. and MacDiarmid, A.G.},
abstractNote = {Despite great theoretical and technological interest in polyacetylene, (CH)/sub x/, the basic features of its band structure have not been unambiguously resolved. Since photoconductivity and optical absorption data have frequently been used to infer information on the band structure of semiconductors, such measurements were carried out on (CH)/sub x/. The main results of an extensive study of the photoconductivity (..delta.. sigma/sub ph/) and absorption coefficient (..cap alpha..) in (CH)/sub x/ are presented. The absence of photoconductivity in cis-(CH)/sub x/, despite the similarity in optical properties indicates that ..delta.. sigma/sub ph/ in trans-(CH)/sub x/ is induced by isomerization. It is found that isomerization generates states deep inside the gap that act as safe traps for minority carriers and thereby enhance the photoconductivity. Compensation of trans-(CH)/sub x/ with ammonia appears to decrease the number of safe traps, whereas acceptor doping increases their number. Thus, chemical doping can be used to control the photoconductive response. The energy of safe traps inside the gap is independent of the process used to generate them; indicative of an intrinsic localized defect level in trans-(CH)/sub x/. A coherent picture based on the soliton model can explain these results, including the safe trapping.},
doi = {10.2172/5250751},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1980},
month = {Tue Jan 01 00:00:00 EST 1980}
}

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