TY  - JOUR
A1  - Zu, Fengshuo
A1  - Amsalem, Patrick
A1  - Egger, David A.
A1  - Wang, Rongbin
A1  - Wolff, Christian Michael
A1  - Fang, Honghua
A1  - Loi, Maria Antonietta
A1  - Neher, Dieter
A1  - Kronik, Leeor
A1  - Duhm, Steffen
A1  - Koch, Norbert
T1  - Constructing the Electronic Structure of CH3NH3PbI3 and CH3NH3PbBr3 Perovskite Thin Films from Single-Crystal Band Structure Measurements
JF  - The journal of physical chemistry letters
N2  - Photovoltaic cells based on halide perovskites, possessing remarkably high power conversion efficiencies have been reported. To push the development of such devices further, a comprehensive and reliable understanding of their electronic properties is essential but presently not available. To provide a solid foundation for understanding the electronic properties of polycrystalline thin films, we employ single-crystal band structure data from angle-resolved photoemission measurements. For two prototypical perovskites (CH3NH3PbBr3 and CH3NH3PbI3), we reveal the band dispersion in two high-symmetry directions and identify the global valence band maxima. With these benchmark data, we construct "standard" photoemission spectra from polycrystalline thin film samples and resolve challenges discussed in the literature for determining the valence band onset with high reliability. Within the framework laid out here, the consistency of relating the energy level alignment in perovskite-based photovoltaic and optoelectronic devices with their functional parameters is substantially enhanced.
Y1  - 2019
U6  - https://doi.org/10.1021/acs.jpclett.8b03728
SN  - 1948-7185
VL  - 10
IS  - 3
SP  - 601
EP  - 609
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Wolff, Christian Michael
A1  - Canil, Laura
A1  - Rehermann, Carolin
A1  - Nguyen, Ngoc Linh
A1  - Zu, Fengshuo
A1  - Ralaiarisoa, Maryline
A1  - Caprioglio, Pietro
A1  - Fiedler, Lukas
A1  - Stolterfoht, Martin
A1  - Kogikoski, Junior, Sergio
A1  - Bald, Ilko
A1  - Koch, Norbert
A1  - Unger, Eva L.
A1  - Dittrich, Thomas
A1  - Abate, Antonio
A1  - Neher, Dieter
T1  - Correction to 'Perfluorinated self-assembled monolayers enhance the stability and efficiency of inverted perovskite solar cells' (2020, 14 (2), 1445−1456)
T2  - ACS nano
Y1  - 2020
U6  - https://doi.org/10.1021/acsnano.0c08081
SN  - 1936-0851
SN  - 1936-086X
VL  - 14
IS  - 11
SP  - 16156
EP  - 16156
PB  - American Chemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Zhao, Yuhang
A1  - Opitz, Andreas
A1  - Eljarrat, Alberto
A1  - Kochovski, Zdravko
A1  - Koch, Christoph
A1  - Koch, Norbert
A1  - Lu, Yan
T1  - Kinetic study on the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane on Ag nanoparticles in chloroform
BT  - implications for the charge transfer complex of Ag-F(4)TCNQ
JF  - ACS applied nano materials
N2  - In this study, the kinetics of the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) on the surface of Ag nanoparticles (Ag NPs) in chloroform has been intensively investigated, as molecular doping is known to play a crucial role in organic electronic devices. Based on the results obtained from UV-visible (vis)-near-infrared (NIR) absorption spectroscopy, cryogenic transmission electron microscopy, scanning nanobeam electron diffraction, and electron energy loss spectroscopy, a two-step interaction kinetics has been proposed for the Ag NPs and F(4)TCNQ molecules, which includes the first step of electron transfer from Ag NPs to F(4)TCNQ indicated by the ionization of F(4)TCNQ and the second step of the formation of a Ag-F(4)TCNQ complex. The whole process has been followed via UV-vis-NIR absorption spectroscopy, which reveals distinct kinetics at two stages: the instantaneous ionization and the long-term complex formation. The kinetics and the influence of the molar ratio of Ag NPs/F(4)TCNQ molecules on the interaction between Ag NPs and F(4)TCNQ molecules in an organic solution are reported herein for the first time. Furthermore, the control experiment with silica-coated Ag NPs manifests that the charge transfer at the surface between Ag NPs and F(4)TCNQ molecules is prohibited by a silica layer of 18 nm.
KW  - Ag nanoparticles
KW  - F(4)TCNQ
KW  - phase transfer
KW  - kinetics
KW  - electron transfer
KW  - surface interaction
Y1  - 2021
U6  - https://doi.org/10.1021/acsanm.1c02153
SN  - 2574-0970
VL  - 4
IS  - 11
SP  - 11625
EP  - 11635
PB  - American Chemical Society
CY  - Washington
ER  -