Defect Engineering in ..pi..-Conjugated Polymers

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm902031n· OSTI ID:975399

Liang, Z; Nardes, A; Wang, D; Berry, J J; Gregg, B A

The optoelectronic properties of thin films of poly(3-hexylthiophene) (P3HT) are markedly improved by treating the polymer in solution with either electrophiles or nucleophiles. The work function is strongly decreased by treatment with lithium aluminum hydride, consistent with hydride ion addition and the observed {approx}400-fold decrease in p-type defect density. The exciton diffusion length (L{sub ex}) doubled to 14 nm, while the bulk carrier mobility ({mu}) improved by more than an order of magnitude to 2.4 x 10{sup -3} cm{sup 2}/(Vs). The work function is increased after treatment with dimethylsulfate, which is consistent with methyl cation addition and, again, both L{sub ex} and {mu} are increased substantially. Both treatments greatly improve the polymer's stability against photo-oxidation. We discuss these results in the framework of defect engineering in organic semiconductors, in analogy to defect engineering studies of inorganic semiconductors.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO.
• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 975399
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 20, 2009 Vol. 21; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM
CARRIER MOBILITY
CATIONS
Chemical and Biosciences
Chemical and Material Sciences
DEFECTS
DIFFUSION LENGTH
EXCITONS
HYDRIDES
LITHIUM
ORGANIC SEMICONDUCTORS
POLYMERS
STABILITY
THIN FILMS
WORK FUNCTIONS