High‐Efficiency Asymmetric Spin Transport Enabled by Nanocolumn Molecular Semiconductors

ABSTRACT Owing to weak spin‐orbit coupling, molecular semiconductors are among the few materials supporting room‐temperature spin functionality, yet their low spin‐transport efficiency ( η s , ∼5%) limits applications. Here, we report molecular spintronic devices featuring vertically asymmetric nanocolumn channels formed by phase separation. These channels confine spins and generate built‐in electric fields, boosting room‐temperature η s to 20%—the highest value reported to date, over five times that of unstructured films. Simultaneously, the nanocolumn channels induce pronounced bias‐dependent asymmetry, with η s of 20% at +0.2 V versus 1% at −0.2 V, yielding a record asymmetry factor, significantly outperforming other material systems (e.g., metal oxides, 2D materials, conventional molecular/inorganic semiconductors). This dual achievement of record‐high efficiency and strong asymmetry establishes a platform for new spintronic functionalities. As a proof of concept, we demonstrate its potential for information‐secure applications via spin‐signal encryption elements and two‐stage spin true random number generators, integrating structural design with spintronic operation.