Publications de Iwan Zimmermann

Charge Extraction and Recombination Dynamics of CdSe/CdTe Solar Cells Studied with Transient Photovoltage/Photocurrent Techniques

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Lei Chen

Significant advancements have been made in the development of high-performance cadmium telluride (CdTe)-based thin film solar cells. However, studies examining the transient excited-state charge dynamics, which determine the final steady-state device perfo ...

IEEE2023

Insight into Lipopolysaccharide Translocation by Cryo-EM structures of a LptDE Transporter in Complex with Pro-Macrobodies

Henning Paul-Julius Stahlberg, Dongchun Ni, Iwan Zimmermann, Denis Bucher

2021

Hole-Transporting Materials for Perovskite Solar Cells Employing an Anthradithiophene Core

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Hiroyuki Kanda, Inés Garcia Benito

A decade after the report of the first efficient perovskite-based solar cell, development of novel hole-transporting materials (HTMs) is still one of the main topics in this research field. Two of the main advance vectors of this topic lie in obtaining mat ...

AMER CHEMICAL SOC2021

Nanoscale Mass-Spectrometry Imaging of Grain Boundaries in Perovskite Semiconductors

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Hiroyuki Kanda, Paul Gratia, Tom Theodorus Antonius Lummen

Incorporation of alkali metals such as Cs+, Rb+, and K+ into hybrid organic-inorganic halide lead perovskites (HOIPs) generally improves the optoelectronic properties of HOIPs. However, it is still uncertain how alkali metals interact and distribute within ...

2020

Development of an inorganic cesium carbonate-based electron transport material for a 17% power conversion efficiency perovskite solar cell device

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Tom Theodorus Antonius Lummen, Brahim Aissa

A low-temperature solution process technique is employed to develop an inorganic cesium carbonate (Cs2CO3) as an electron transport material for inorganic-organic hybrid double cation (FAPbI(3))(0.85)(MAPbBr(3))(0.15) perovskite solar cells, as an alternat ...

2020

Surface, Interface, and Bulk Electronic and Chemical Properties of Complete Perovskite Solar Cells: Tapered Cross-Section Photoelectron Spectroscopy, a Novel Solution

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Thomas Mayer

The surface, interface, and bulk properties are a few of the most critical factors that influence the performance of perovskite solar cells. The photoelectron spectroscopy (PES) is used as a technique to analyze these properties. However, the information d ...

AMER CHEMICAL SOC2020

Tapered Cross-Section Photoelectron Spectroscopy of State-of-the-Art Mixed Ion Perovskite Solar Cells: Band Bending Profile in the Dark, Photopotential Profile Under Open Circuit Illumination, and Band Diagram

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Thomas Mayer

The purpose of this article is twofold. On the one hand the method of spacial resolved photoemission spectroscopy on small angle tapered cross-sections (TCS) of complete devices is introduced to analyze simultaneously the chemical and electronic structure. ...

WILEY-V C H VERLAG GMBH2020

Atomic Layer-Deposited Aluminum Oxide Hinders Iodide Migration and Stabilizes Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Iwan Zimmermann

Iodide migration causes degradation of the perovskite solar cells. Here, we observe the direct migration of iodide into the hole-transport layer in a device. We demonstrate that ultrathin room temperature atomic layer-deposited Al2O3 on the perovskite surf ...

ELSEVIER2020

Tetrasubstituted Thieno[3,2-b]thiophenes as Hole-Transporting Materials for Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Inés Garcia Benito, Tom Theodorus Antonius Lummen, Javier Urieta Mora

Three hole-transporting materials (HTMs) were prepared following a straightforward synthetic route by cross-linking arylamine-based ligands with a simple thieno[3,2-b]thiophene (TbT) core. The novel HTMs were fully characterized with standard techniques to ...

2020

Hole transporting materials for perovskite solar cells and a simple approach for determining the performance limiting factors

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Tom Theodorus Antonius Lummen

The synthesis and characterization of three novel HTMs with different highest occupied molecular orbital (HOMO) energy levels and their performances in MAPbI(3)-based devices in comparison with Spiro-OMeTAD is reported. Without systematic optimization, the ...

Royal Society of Chemistry2020