Ass.-Prof. Dr. Laerte Patera
Surface Chemistry
Our research aims at obtaining mechanistic insight into atomic-scale chemical processes occurring at surfaces. Current research topics span from the synthesis and imaging of two-dimensional covalent organic frameworks for energy conversion. We use imaging techniques based on high-resolution scanning probe microscopy to visualize molecular nanostructures at the atomic scale. Special attention is given to the development of novel imaging approaches to resolve photoexcited states in light-harvesting functional materials. Understanding light-induced processes will drive the design of photoactive materials with improved energy conversion efficiency.
Scanning tunnelling microscopy (STM) images of a two-dimensional metal-organic framework.
Covalent organic frameworks (COFs) are materials formed by the linkage of organic building blocks to create periodic structures. This enables the construction of tailor-made systems for applications in (photo-)catalysis and optoelectronics. The formation of extended COFs is achieved through on-surface synthesis, which makes use of atomically flat surfaces as templates to confine polymerization reactions in two dimensions. The COFs are characterized at the atomic scale by high-resolution scanning tunneling microscopy (STM) and near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), shedding light onto the reaction pathways leading to the growth of COFs.
Sketch of the experimental setup for the investigation of photoexcited states in two-dimensional organic frameworks.
Excitons are fundamental light-induced excitations, composed of bound electron-hole pairs. While they lie at the heart of photochemistry, their short-lived nature makes their experimental study a real challenge.
In the context of the recently awarded ERC starting grant (WEPOF), we are working on novel imaging techniques based on scanning probe microscopy to resolve photoexcited states in organic frameworks.