Atomic scale investigation of molecular adsorption on all-inorganic perovskite solar-cell materials

• Applicant: Professor Dr. M. Alexander Schneider
• Subject Area: Experimental Condensed Matter Physics ; Solid State and Surface Chemistry, Material Synthesis
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567917152

The recently developed, highly efficient perovskite solar cells contain charge transport layers to facilitate the transport of charge carriers away from the light absorbing material. Layers of functional, organic molecules are often used for this purpose since they are easily processable and can also be adapted to suit a particular functionality. Furthermore, such molecular layers are also useful to stabilize the perovskite solar cell, seal it from harmful external influences and thus lead to an increased lifetime of the cell. Unfortunately, most of the processes behind this are unexplored on the atomic scale. In this project the adsorption and interaction of various functional molecules and typical solvents on and with the surface of exemplary chosen CsPbBr3 and CsSnBr3 perovskite thin films is studied experimentally. To this end, scanning tunneling microscopy and spectroscopy at low temperatures and ultra-high vacuum will be employed. The project aims at understanding the interaction between molecule and surface but also between neighboring molecules. This will be achieved by determining the adsorption geometry of single molecules and of self-assembled molecular layers and by resolving their most relevant electronic properties. Particularly, the combination of functional and solvent molecules will be studied paradigmatically to mimic the situation encountered in the production of solar cells and other optoelectronic devices based on perovskite materials.

• DFG Programme: Research Grants