Microcrystal Electron Diffraction for Molecular Design of Functional Non-Fullerene Acceptor Structures
Steve Halaby1, Michael Martynowycz1, Ziyue Zhu2
1Howard Hughes Medical Institute, David Geffen School of Medicine, Department of Biological Chemistry and Physiology, University of California, Los Angeles, California 90095, United States.
Chemistry of Materials : a Publication of the American Chemical Society
|March 21, 2023
Summary
This study uses microcrystal electron diffraction (MicroED) to reveal the atomic structures of organic semiconductors (OSCs). This method aids in designing new materials with enhanced optoelectronic properties by understanding molecular packing.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Organic Electronics
Background:
- Designing organic semiconductors (OSCs) with improved optoelectronic properties requires understanding molecular structure-solid-state arrangement relationships.
- Determining the precise atomic structure of OSCs, particularly non-fullerene acceptors (NFAs), is a significant challenge.
Purpose of the Study:
- To determine the lattice organization of two NFAs using microcrystal electron diffraction (MicroED).
- To identify new polymorphs and understand structure-property relationships in NFAs.
- To guide the design of novel OSCs and NFAs with enhanced performance.
Main Methods:
- Microcrystal electron diffraction (MicroED) for atomic structure determination of NFAs.
- X-ray crystallography (for comparison, highlighting limitations).
- Advanced electronic structure calculations.
Main Results:
- Determined the lattice organization of o-IDTBR from a powder sample without prior crystallization.
- Identified a new polymorph of ITIC-Th, exhibiting the most distorted backbone among known NFAs.
- Electronic structure calculations revealed that 3D wire mesh topologies facilitate robust charge transport in NFA crystals.
Conclusions:
- MicroED is a powerful technique for NFA structure determination, especially for microcrystalline or non-crystallizable samples.
- Understanding molecular packing and electronic coupling is crucial for optimizing charge transport in OSCs.
- This integrated approach accelerates the discovery and design of next-generation organic electronic materials.
