Ultrafast Charge Separation at a Single-walled Carbon Nanotube – Polymer Interface

We report the observation of an ultrafast (~ 430 fs) charge transfer process at the interface between a single-walled carbon nanotube (SWNT) wrapped by a semi-conducting polymer, poly(3-hexylthiophene) (P3HT), creating free polarons on both materials. The addition of excess P3HT as a surrounding network allows these free polarons to be long-lived at room temperature. Our results suggest that SWNT-P3HT blends incorporating only 1% fractions of SWNTs can achieve a charge separation efficiency comparable to a conventional 60:40 P3HT-fullerene blend, provided small-diameter tubes are embedded in an excess P3HT matrix.

[1]  M. Johnston,et al.  The role of ultrafast torsional relaxation in the emission from polythiophene aggregates , 2010, 2010 Conference on Optoelectronic and Microelectronic Materials and Devices.

[2]  H. Snaith,et al.  Synthesis and spectroscopic characterization of solution processable highly ordered polythiophene–carbon nanotube nanohybrid structures , 2010, Nanotechnology.

[3]  H. Ohkita,et al.  Near-IR femtosecond transient absorption spectroscopy of ultrafast polaron and triplet exciton formation in polythiophene films with different regioregularities. , 2009, Journal of the American Chemical Society.

[4]  R. Nicholas,et al.  Observation of a type II heterojunction in a highly ordered polymer-carbon nanotube nanohybrid structure. , 2009, Nano letters.

[5]  J. Kuo,et al.  Energy Transfer from Photo-Excited Fluorene Polymers to Single-Walled Carbon Nanotubes , 2009 .

[6]  J. Parisi,et al.  Femtosecond up-conversion technique for probing the charge transfer in a P3HT : PCBM blend via photoluminescence quenching , 2009 .

[7]  W. Blau,et al.  Enhanced device performance using different carbon nanotube types in polymer photovoltaic devices , 2008 .

[8]  Taiha Joo,et al.  Effect of SWNT Defects on the Electron Transfer Properties in P3HT/SWNT Hybrid Materials , 2008 .

[9]  L. Herz,et al.  Dynamics of excited-state conformational relaxation and electronic delocalization in conjugated porphyrin oligomers. , 2008, Journal of the American Chemical Society.

[10]  R. Nicholas,et al.  Direct spectroscopic evidence of energy transfer from photo-excited semiconducting polymers to single-walled carbon nanotubes , 2008, Nanotechnology.

[11]  Chun-Wei Chen,et al.  Polymer structure and solvent effects on the selective dispersion of single-walled carbon nanotubes. , 2008, Journal of the American Chemical Society.

[12]  Daniel Moses,et al.  Photoinduced Carrier Generation in P3HT/PCBM Bulk Heterojunction Materials , 2008 .

[13]  J. Grossman,et al.  Role of semiconducting and metallic tubes in P3HT/carbon-nanotube photovoltaic heterojunctions: density functional theory calculations. , 2008, Nano letters.

[14]  Y. Franghiadakis,et al.  Effective mobility and photocurrent in carbon nanotube–polymer composite photovoltaic cells , 2007 .

[15]  R. Nicholas,et al.  Highly selective dispersion of single-walled carbon nanotubes using aromatic polymers. , 2007, Nature nanotechnology.

[16]  R. Friend,et al.  Role of intermolecular coupling in the photophysics of disordered organic semiconductors: aggregate emission in regioregular polythiophene. , 2007, Physical review letters.

[17]  Xiaoniu Yang,et al.  The Effect of Thermal Treatment on the Morphology and Charge Carrier Dynamics in a Polythiophene–Fullerene Bulk Heterojunction , 2005 .

[18]  J. Warman,et al.  Electrodeless time-resolved microwave conductivity study of charge-carrier photogeneration in regioregular poly(3-hexylthiophene) thin films , 2004 .

[19]  Carlos Silva,et al.  Exciton regeneration at polymeric semiconductor heterojunctions. , 2004, Physical review letters.

[20]  Christian Thomsen,et al.  Carbon Nanotubes: Basic Concepts and Physical Properties , 2004 .

[21]  R. Österbacka,et al.  Photoexcitations in Regio-regular and Regio-random Polythiophene Films , 2003 .

[22]  T. Pedersen.  Variational approach to excitons in carbon nanotubes , 2003 .

[23]  R. Österbacka,et al.  Photoexcitation dynamics in regioregular and regiorandom polythiophene films , 2001 .

[24]  Jiang,et al.  Two-dimensional electronic excitations in self-assembled conjugated polymer nanocrystals , 2000, Science.

[25]  C. Tang.  Two‐layer organic photovoltaic cell , 1986 .