Solvent-Free Coating of Highly Uniform Ultrathin Semiconductor Layers Now Possible
Researcher unlocked a novel approach to organic semiconductors fabrication by harnessing the self-organization capabilities of molecular cocrystals. Organic semiconductor molecules typically consist of rigid π-electron skeletons and flexible alkyl chains, which influence their structural and electronic properties. This study reveals that blending two distinct organic semiconductors—one with symmetrical alkylation and the other with asymmetrical alkylation—significantly enhances liquid crystallization and self-organized superlayer cocrystal formation.
Using the well-known rod-shaped centrosymmetric π-electron skeleton of BTBT, the researchers discovered that when two structurally different alkylated derivatives are mixed in a 1:1 ratio, they readily self-assemble into a supramolecular multilayer structure. This self-organization occurs due to a unique pairing mechanism, where π-electron skeleton layers and alkyl layers stack in an orderly fashion, forming a highly stable and uniform superlayer cocrystal.
Notably, this supramolecular layering paves the way for the solvent-free deposition of ultrathin, homogeneous organic semiconductor films. The layered liquid-crystal phase enables precise molecular arrangement without requiring organic solvents, which are often hazardous to human health and the environment. This breakthrough offers a promising path toward sustainable, high-performance organic electronics by reducing reliance on toxic chemicals and enhancing the structural control of semiconductor layers.
Beyond its technological implications, this discovery deepens our understanding of spontaneous aggregation behaviors in soft matter, shedding light on the formation of liquid-crystalline and crystalline phases. By leveraging these self-organizing principles, researchers aim to develop next-generation green semiconductor manufacturing techniques with minimal environmental impact.
This pioneering work marks a significant step toward eco-friendly, high-precision organic electronics, bringing solvent-free, self-assembled semiconductor coatings closer to practical applications.
Papers
Journal: Science Advances
Title: Melt-mixed superlayer cocrystal formation using symmetric and unsymmetric organic semiconductors
Authors: Kiyoshi Nikaido*, Seita Kuroda, Satoru Inoue, Tatsuo Hasegawa*
DOI: 10.1126/sciadv.adv1878