Fig. 2: Dislocation analysis in organic optoelectronic materials.
From: Microscopic crystallographic analysis of dislocations in molecular crystals
a, p-Terphenyl molecule and p-terphenyl unit cell. b, ADF-STEM image, dislocation network (green lines tracing the diffraction contrast features of dislocations) and average diffraction pattern extracted from a single SED (4D-STEM) dataset. The diffraction pattern indexes to the [001] zone axis. c, Polar plot of the bend contour displacements at the solid dislocation line highlighted in b for a series of ghkl values as a function of φ. The red trace marks a fit to equation (1), with the measured displacements in blue. Two VDF images corresponding to the displacements marked as (i) and (ii) depicting bend contours at the ghkl ∙ B = 0 and ghkl ∙ B ≠ 0 conditions, respectively. The indices hkl are marked on the individual VDF images. d, p-Terphenyl unit cell oriented to match the sample orientation. The magenta arrow marks the Burgers vector B = [010]. e, Anthracene molecule and unit cell. f, ADF-STEM image and the overlaid dislocation network extracted from the image contrast. The image in the inset shows the average diffraction pattern of the entire field of view indexed to the [101] zone axis. g, Polar plot of the bend contour displacement as a function of φ for the solid green dislocation line highlighted in f. The red trace marks a fit to equation (1) with the measured displacements in blue. h, Anthracene unit cell oriented to match the sample orientation. The magenta arrow marks the Burgers vector B = [010].
