title: Ultrafast Hole Transfer from (6,5) SWCNT to P3HT:PCBM Blend by Resonant Excitation.
abstract: Nowadays, SWCNTs are envisaged to enhance the charge separation or transport of conjugated polymer-fullerene derivatives blends. In this work we studied, by means of ultrafast transient absorption spectroscopy, three components blends in which commercially available SWCNTs are added to the standard bulk heterojunction. We explored three different configurations that give rise to diverse interfacing scenarios. We found strong evidence of a direct hole transfer from photoexcited SWCNTs to the P3HT polymer. The transfer efficiency depends on the interface configuration. It is the highest for the blend where we achieve closer contact between the (6,5) SWCNTs and the polymer. When the polymer blend is deposited on top of the nanotube film or the nanotube film is deposited onto the polymer blend, the process is slowed down due to less or missing interfacing of the carbon nanotubes with the polymer chains. Additionally we demonstrate a cascading effect in the electron path, which stabilizes charge separation by further transferring the electron left behind by hole transfer to the polymer to the adjacent (7,5) SWCNTs. Our results highlight the potential of semiconducting SWCNTs to improving the performance of organic solar cells.
authors: Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia (IIT) , Via Giovanni Pascoli, 70/3, 20133 Milan, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Diana Gisell
authors: DG
authors: Figueroa Del Valle
authors: Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Luca
authors: L
authors: Moretti
authors: Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia (IIT) , Via Giovanni Pascoli, 70/3, 20133 Milan, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Isis
authors: I
authors: Maqueira-Albo
authors: Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia (IIT) , Via Giovanni Pascoli, 70/3, 20133 Milan, Italy.|Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Eduardo
authors: E
authors: Aluicio-Sarduy
authors: Department of Nanochemistry, Istituto Italiano di Tecnologia (IIT) , Via Morego, 30, 16163 Genova, Italy.
authors: Ilka
authors: I
authors: Kriegel
authors: Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia (IIT) , Via Giovanni Pascoli, 70/3, 20133 Milan, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Guglielmo
authors: G
authors: Lanzani
authors: Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia (IIT) , Via Giovanni Pascoli, 70/3, 20133 Milan, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.|Istituto di Fotonica e Nanotecnologie CNR , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Francesco
authors: F
authors: Scotognella