Self-Assembly Polymorphism of Regioisomeric Diketopyrrolopyrrole-Based π‑Conjugated Organic Semiconductors

Jinxing Li (1) , Xinrui Miao (2) , Lei Ying (3) , Fabien Silly (4) , Chunshan Che , Gang Kong , Wenli Deng (1)

1 SUSTech - Southern University of Science and Technology
2 SCUT - South China University of Technology [Guangzhou]
3 NINGBO UNIVERSITY
4 LEPO - Laboratoire d'Electronique et nanoPhotonique Organique

The 2D molecular assemblies of two structural isomers p-DBPy and d-DBPy relevant to the field of organic electronics. These two molecules only differ in the position of pyridyl N-atoms,. The solution concentration and solvent effects on the adlayer morphology are investigated using scanning tunneling microscopy (STM). Both kinds of molecules could exhibit obviously different molecular conformations and packing patterns, which demonstrate that the variation of the N-atom position in the pyridyl leads to different intermolecular interactions and stacking styles. Positioning the pyridyl N-atoms proximal to the central conjugated core could change the molecular conformation into a banana shape by bending the molecule, however, the d-DBPy molecule in which pyridyl N-atoms are distal to the central conjugated cores keep a linear shape in the monolayer. This work illustrates that altering the position of N-atoms in pyridyl could influence the film morphology and provides a deeper insight from molecular scale to understand the molecular conformation in different packing patterns, which are benefit for the rational design of future advanced optoelectronic devices.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Jinxing Li, Xinrui Miao, Lei Ying, Fabien Silly, Chunshan Che, et al.. Self-Assembly Polymorphism of Regioisomeric Diketopyrrolopyrrole-Based π‑Conjugated Organic Semiconductors. Journal of Physical Chemistry C, 2019, 123 (2), pp.1185-1193. ⟨10.1021/acs.jpcc.8b08701⟩. ⟨hal-02433442⟩