Year: 2026
Type: preprint
Abstract: The chirality-induced spin selectivity (CISS) effect has attracted increasing attention for its unique ability to generate spin-polarized currents without magnetic components, with promising applications in spintronics, optoelectronics, and electrocatalysis. Although a wide range of chiral materials have been demonstrated to exhibit the CISS effect, most reported systems are based on amorphous films, self-assembled monolayers, or supramolecular assemblies, where structural disorder and aggregative traps compromise reliable evaluation of the CISS effect and obscure the structure-property relationship. Here, we overcome these limitations by constructing high-quality single crystals of chiral BN-embedded double helicenes, which feature a rigid chiral backbone and ordered molecular packing. Using magnetic conductive atomic force microscopy, we show that the single-crystal platform yields significantly improved current uniformity and measurement reproducibility compared with spin-coated thin films. Taking advantage of this enhanced reliability, we systematically investigated spin-selective transport in single crystals with thicknesses ranging from 18 to 330 nm. The spin polarization initially increases rapidly with crystal thickness, reaches a broad maximum, and remains pronounced over transport distances of up to 330 nm. This thickness-dependent behavior provides direct evidence for the cumulative spinselective transport along the long-range ordered structure, thereby distinguishing intrinsic bulk spin polarization from interfacial contributions. Our results thus establish chiral organic single crystals as a robust platform for investigating the CISS effect and unveiling clear structureproperty correlations.
Source: ChemRxiv
Institutions: Nankai University, Tianjin University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223122924