TY  - JOUR
A1  - Tremel, Kim
A1  - Fischer, Florian S. U.
A1  - Kayunkid, Navaphun
A1  - Di Pietro, Riccardo
A1  - Tkachov, Roman
A1  - Kiriy, Anton
A1  - Neher, Dieter
A1  - Ludwigs, Sabine
A1  - Brinkmann, Martin
T1  - Charge transport anisotropy in highly oriented thin films of the acceptor polymer P(NDI2OD-T2)
JF  - dvanced energy materials
N2  - The nanomorphology of the high mobility polymer poly{[N,N'-bis(2-octyldodecyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} P(NDI2OD-T2) in thin films is explored as a function of different annealing conditions and correlated to optical and electrical properties. While nanofibrils with face-on orientation in form I are obtained directly after spin-coating and annealing below the melt transition temperature, clear evidence of lamellar structures is found after melt-annealing followed by slow cooling to room temperature. Interestingly these structural changes are accompanied by distinct changes in the absorption patterns. Electron diffraction measurements further show clear transitions towards predominant edge-on oriented chains in form II upon melt-annealing. Large-scale alignment with dichroic ratios up to 10 and improved order is achieved by high temperature rubbing and subsequent post-rubbing annealing. These highly oriented morphologies allow anisotropic in-plane charge transport to be probed with top-gate transistors parallel and perpendicular to the polymer chain direction. Mobilities up to 0.1 cm(2) V-1 s(-1) are observed parallel to the polymer chain, which is up to 10 times higher than those perpendicular to the polymer chain.
Y1  - 2014
U6  - https://doi.org/10.1002/aenm.201301659
SN  - 1614-6832
SN  - 1614-6840
VL  - 4
IS  - 10
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Albrecht, Steve
A1  - Vandewal, Koen
A1  - Tumbleston, John R.
A1  - Fischer, Florian S. U.
A1  - Douglas, Jessica D.
A1  - Frechet, Jean M. J.
A1  - Ludwigs, Sabine
A1  - Ade, Harald W.
A1  - Salleo, Alberto
A1  - Neher, Dieter
T1  - On the efficiency of charge transfer state splitting in polymer: Fullerene solar cells
JF  - Advanced materials
KW  - organic solar cells
KW  - charge generation
KW  - geminate recombination
KW  - charge transfer states
KW  - driving force
KW  - excess energy
KW  - morphology
KW  - spectroelectrochemistry
Y1  - 2014
U6  - https://doi.org/10.1002/adma.201305283
SN  - 0935-9648
SN  - 1521-4095
VL  - 26
IS  - 16
SP  - 2533
EP  - 2539
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fischer, Florian S. U.
A1  - Trefz, Daniel
A1  - Back, Justus
A1  - Kayunkid, Navaphun
A1  - Tornow, Benjamin
A1  - Albrecht, Steve
A1  - Yager, Kevin G.
A1  - Singh, Gurpreet
A1  - Karim, Alamgir
A1  - Neher, Dieter
A1  - Brinkmann, Martin
A1  - Ludwigs, Sabine
T1  - Highly Crystalline Films of PCPDTBT with Branched Side Chains by Solvent Vapor Crystallization: Influence on Opto-Electronic Properties
JF  - Advanced materials
N2  - PCPDTBT, a marginally crystallizable polymer, is crystallized into a new crystal structure using solvent-vapor annealing. Highly ordered areas with three different polymer-chain orientations are identified using TEM/ED, GIWAXS, and polarized Raman spectroscopy. The optical and structural properties differ significantly from films prepared by standard device preparation protocols. Bilayer solar cells, however, show similar performance.
Y1  - 2015
U6  - https://doi.org/10.1002/adma.201403475
SN  - 0935-9648
SN  - 1521-4095
VL  - 27
IS  - 7
SP  - 1223
EP  - 1228
PB  - Wiley-VCH
CY  - Weinheim
ER  -