Atomic Force Microscope with Glovebox-Cluster

• Subject Area: Chemical Solid State and Surface Research
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 547891568

In this proposal, we apply for a glovebox with an integrated atomic force microscope (AFM). The instrument will be used to characterize self-assembled monolayers (SAMs) suited for perovskite solar cells (PSCs) and to study the effectiveness of surface passivation to enhance charge carrier collection in these devices. Halide perovskites are a hot contender for the next generation of photovoltaics combining favorable optoelectronic properties, low cost and solution processability in one material. Although PSCs underwent a tremendous increase in efficiency over the last decade and can nowadays rival even state-of-the-art silicon photovoltaics, the bottleneck holding back this promising technique from commercialization is the relatively poor long-term stability of the PSC devices and the use of toxic lead in perovskite absorber. Overcoming these challenges is the main focus of research in our group. SAMs can be a powerful tool to manipulate and tune the device’s interface and increase its stability and efficiency. They can optimize the energy offset between different layers, reduce non-radiative recombination and hysteresis and passivate surface defects. They can also replace the classical electron and hole transport layer used in PSCs, which we want to study in our new laboratory in Bielefeld. We plan to use the applied instrument in two distinct projects. In the first project, we want to use AFM measurements as one method of characterization to explore different aspects of SAMs relevant to PSCs, like the topography of the monolayer, its energy alignment to adjacent layers or the mobility of the molecules at high temperatures. An AFM, which allows high-resolution imaging, and surface potential measurements by Kelvin probe force microscopy (KPFM), and it is equipped with a unit for heating the sample is needed for this. In our second project, we want to investigate the effectiveness of surface passivation in enhancing charge carrier collection in PSCs. We plan to use conductivity and photoconductivity measurements to assess the surface response of the perovskite to light excitation. For this purpose, the applied instrument must be able to illuminate the sample and perform conductivity measurements with C-AFM. These studies will help us find improved passivation layers for lower surface recombination, leading to more efficient devices. The instrument must be situated inside of a glovebox for both projects because halide perovskites are susceptible to many intrinsic and extrinsic degradation factors, such as moisture and oxygen, making handling them under an inert atmosphere crucial. All the experiments will be done in close cooperation with our group members at the Helmholtz Centre in Berlin as well as the working group of Prof. Dr. Angelika Kühnle at Bielefeld University, allowing us to combine our knowledge of synthesis, characterization and theoretical calculations to help advance this promising photovoltaic technique to commercialization.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Rasterkraftmikroskop mit Glovebox-Cluster
• Instrumentation Group: 5091 Rasterkraft-Mikroskope
• Applicant Institution: Universität Bielefeld
• Leader: Professor Antonio Abate, Ph.D.