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Unambiguous Diagnosis of Photoinduced Charge Carrier Signatures in a Stoichiometrically Controlled Semiconducting Polymer-Wrapped Carbon Nanotube Assembly.
- Source :
- Angewandte Chemie International Edition; 7/6/2015, Vol. 54 Issue 28, p8133-8138, 6p
- Publication Year :
- 2015
-
Abstract
- Single-walled carbon nanotube (SWNT)-based nanohybrid compositions based on (6,5) chirality-enriched SWNTs ([(6,5) SWNTs]) and a chiral n-type polymer (SPBN(b)-Ph<subscript>4</subscript>PDI) that exploits a perylenediimide (PDI)-containing repeat unit are reported; S-PBN(b)-Ph<subscript>4</subscript>PDI-[(6,5) SWNT] superstructures feature a PDI electron acceptor unit positioned at 3 nm intervals along the nanotube surface, thus controlling rigorously SWNT-electron acceptor stoichiometry and organization. Potentiometric studies and redox-titration experiments determine driving forces for photoinduced charge separation (CS) and thermal charge recombination (CR) reactions, as well as spectroscopic signatures of SWNT hole polaron and PDI radical anion (PDI<superscript>-.</superscript>) states. Time-resolved pump-probe spectroscopic studies demonstrate that SPBN(b)-Ph<subscript>4</subscript>PDI-[(6,5) SWNT] electronic excitation generates PDI<superscript>-.</superscript> via a photoinduced CS reaction (t<subscript>CS</subscript>≈0.4 ps, Φ<subscript>CS</subscript> ≈0.97). These experiments highlight the concomitant rise and decay of transient absorption spectroscopic signatures characteristic of the SWNT hole polaron and PDI¢C states. Multiwavelength global analysis of these data provide two charge-recombination time constants (t<subscript>CR</subscript>≈31.8 and 250 ps) that likely reflect CR dynamics involving both an intimately associated SWNT hole polaron and PDI<superscript>-.</superscript> charge-separated state, and a related charge-separated state involving PDI<superscript>-.</superscript> and a hole polaron site produced via hole migration along the SWNT backbone that occurs over this timescale. [ABSTRACT FROM AUTHOR]
- Subjects :
- CHARGE carrier capture
SEMICONDUCTORS
CARBON nanotubes
ELECTROPHILES
STOICHIOMETRY
Subjects
Details
- Language :
- English
- ISSN :
- 14337851
- Volume :
- 54
- Issue :
- 28
- Database :
- Complementary Index
- Journal :
- Angewandte Chemie International Edition
- Publication Type :
- Academic Journal
- Accession number :
- 108795012
- Full Text :
- https://doi.org/10.1002/anie.201501364