3D Electron Diffraction as GIWAXS Alternative for Quantitative Structural Characterization of Organic Solar Cells

We demonstrate elastically filtered 3D Electron Diffraction (3D ED) as a powerful alternative technique to Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS) for quantitatively characterizing the structure of organic semiconductor films. Using a model material system of solvent vapor annealed DRCN5T:PC71BM thin film, which is employed in organic solar cells (OSCs), we extract the structural data obtained from 3D ED and compare with that from GIWAXS, utilizing both laboratory and synchrotron X-ray sources. Quantitative evaluation of the datasets in terms of peak positions, peak widths and mosaicity revealed good agreement between both techniques, qualifying 3D ED as an alternative tool for analyzing highly beam-sensitive organic thin films. Furthermore, the respective advantages and limitations of 3D ED and GIWAXS are discussed, emphasizing the unique capability of 3D ED to integrate seamlessly with the diverse imaging and spectroscopic modalities in modern TEM. This integration enriches the techniques of structural characterization of OSCs, paving the way for deeper insights into their structural properties and ultimately their performance.