Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Final technical report, March 19, 1979-March 18, 1980
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.
- Research Organization:
- Univ. of Pennsylvania, Philadelphia, PA (United States)
- DOE Contract Number:
- AC04-79ET23002
- OSTI ID:
- 5250751
- Report Number(s):
- DOE/ET/23002-T9
- Country of Publication:
- United States
- Language:
- English
Similar Records
Polyacetylene, (CH)/sub x/, as an emerging material for solar cell applications. Technical progress report, October, November, December 1979
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Related Subjects
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