TY  - JOUR
A1  - Schubert, Marcel
A1  - Frisch, Johannes
A1  - Allard, Sybille
A1  - Preis, Eduard
A1  - Scherf, Ullrich
A1  - Koch, Norbert
A1  - Neher, Dieter
T1  - Tuning side chain and main chain order in a prototypical donor-acceptor copolymer
BT  - implications for optical, electronic, and photovoltaic characteristics
JF  - Elementary Processes in Organic Photovoltaics
N2  - The recent development of donor–acceptor copolymers has led to an enormous improvement in the performance of organic solar cells and organic field-effect transistors. Here we describe the synthesis, detailed characterisation, and application of a series of structurally modified copolymers to investigate fundamental structure–property relationships in this class of conjugated polymers. The interplay between chemical structure and optoelectronic properties is investigated. These are further correlated to the charge transport and solar cell performance, which allows us to link their chemical structure to the observed physical properties.
KW  - Aggregate states
KW  - All-polymer heterojunctions
KW  - Alternating copolymers
KW  - Ambipolar charge transport
KW  - Ambipolar materials
KW  - Backbone modifications
KW  - Bilayer solar cells
KW  - Charge separation
KW  - Conformational disorder
KW  - Crystalline phases
KW  - Donor-acceptor copolymers
KW  - Electron traps
KW  - Energetic disorder
KW  - Energy-level alignment
KW  - Fermi-level alignment
KW  - Fermi-level pinning
KW  - Interface dipole
KW  - Interlayer
KW  - Intrachain order
KW  - Intragap states
KW  - Microscopic morphology
KW  - Mobility imbalance
KW  - Mobility relaxation
KW  - Monte Carlo simulation
KW  - Multiple trapping model
KW  - Nonradiative recombination
KW  - OFET
KW  - Open-circuit voltage
KW  - Optoelectronic properties
KW  - Partially alternating copolymers
KW  - Photo-CELIV
KW  - Photocurrent
KW  - Photovoltaic gap
KW  - Polymer intermixing
KW  - Recombination losses
KW  - Spectral diffusion
KW  - Statistical copolymers
KW  - Stille-type cross-coupling
KW  - Structure-property relationships
KW  - Time-dependent mobility
KW  - Time-of-flight (TOF)
KW  - Transient photocurrent
KW  - Ultraviolet photoelectron spectroscopy
KW  - Vacuum-level alignment
KW  - X-ray photoelectron spectroscopy
Y1  - 2016
SN  - 978-3-319-28338-8
SN  - 978-3-319-28336-4
U6  - https://doi.org/10.1007/978-3-319-28338-8_10
SN  - 0065-3195
VL  - 272
SP  - 243
EP  - 265
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wolff, Christian Michael
A1  - Zu, Fengshuo
A1  - Paulke, Andreas
A1  - Perdigón-Toro, Lorena
A1  - Koch, Norbert
A1  - Neher, Dieter
T1  - Reduced Interface-Mediated Recombination for High Open-Circuit Voltages in CH3NH3PbI3 Solar Cells
JF  - Advanced materials
N2  - Perovskite solar cells with all-organic transport layers exhibit efficiencies rivaling their counterparts that employ inorganic transport layers, while avoiding high-temperature processing. Herein, it is investigated how the choice of the fullerene derivative employed in the electron-transporting layer of inverted perovskite cells affects the open-circuit voltage (V-OC). It is shown that nonradiative recombination mediated by the electron-transporting layer is the limiting factor for the V-OC in the cells. By inserting an ultrathin layer of an insulating polymer between the active CH3NH3PbI3 perovskite and the fullerene, an external radiative efficiency of up to 0.3%, a V-OC as high as 1.16 V, and a power conversion efficiency of 19.4% are realized. The results show that the reduction of nonradiative recombination due to charge-blocking at the perovskite/organic interface is more important than proper level alignment in the search for ideal selective contacts toward high V-OC and efficiency.
KW  - electron-transport layers
KW  - nonradiative recombination
KW  - open-circuit voltage
KW  - perovskite solar cells
Y1  - 2017
U6  - https://doi.org/10.1002/adma.201700159
SN  - 0935-9648
SN  - 1521-4095
VL  - 29
PB  - Wiley-VCH
CY  - Weinheim
ER  -