Start of funding 01.01.2021

Formation Dynamics of Structurally Complex Chiral Hybrid Halide Perovskites for Efficient Sustainable Energy Applications

Dr. Felix Deschler
Technische Universität München
Walter Schottky Institute Center for Nanotechnology and Nanomaterials

Dr. Carolin M Sutter-Fella
Lawrence Berkeley National Laboratory
Chemical Sciences Division



To discover and create new materials for energy applications, we need to know how functions relate to structure, synthesis variables, arrangement of atoms and molecules, and how these functions evolve during fabrication. The focus of this project is to develop an understanding of the co-evolution of functional properties in relation to precursor chemistry, involving chiral organics, to discover optimal conditions for reproducible synthesis of structurally highly-complex halide perovskites. Due to their structural and compositional flexibility, these semiconductor materials, which show outstanding optoelectronic properties, have recently emerged as one of the few known bulky semiconductor materials that allow for the introduction of chiral motives. The results from our project could open a whole new range of applications, for instance polarized light-emitting diodes or enantioselective photo-catalysis.

Final report:
In recent years, chiral semiconductors have emerged as the potential foundation for a number of new technologies, including the selective emission and detection of circularly polarized light as well as the generation of circularly spin-polarized charge carriers. A promising material basis are hybrid inorganic-organic lead halide perovskite based on their structural versatility and excellent optoelectrical properties. Likewise, amino acids represent an inexpensive and readily available source for chiral organic precursors. This project set out to explore the potential use of amino acid 3-aminobutyric acid (3-ABA) in the fabrication and functionalization of lead halide perovskites and related materials.

We were able to create 3-ABA-modified thin films of the semiconductor DMAPbI3 which displayed strong circular dichroism effects, a clear indication of chirality. We were further able to demonstrate how 3-ABA influences the formation dynamics of MAPbBr3 and how this can be used to create bright, green emitters with low thresholds for amplified spontaneous emission. Both projects greatly profited from the in-situ spectroscopy techniques available at the Molecular Foundry at Lawrence Berkeley National Laboratory which allowed for valuable insights into the formation dynamics of both material systems. This enabled us to optimize fabrication strategies and to better understand the influence of the organic additive on crystallization process.

In a related project, we investigated the chiral semiconductor (R/S)-EBAPbI3 for the generation and transfer of polarized charge carriers which subsequently were used for the emission of polarized light. This project was enabled by the XRD-based structural in-situ analysis at beamline 12.3.2 at the Advanced Light Source of Lawrence Berkeley National Laboratory.