Organic small‐molecule‐based devices with multilevel electroresistive memory behaviors have attracted more and more attentions due to their super‐high data‐storage density. However, up to now, only ternary memory molecules have been reported, and ternary storage devices may not be compatible with the binary computing systems perfectly. In this work, a donor–acceptor structured molecule containing three electron acceptors is rationally designed and the field‐induced charge‐transfer processes can occur from the donors. Organic quaternary memory devices based on this molecule are successfully demonstrated for the first time. The switching threshold voltages of the memory device are –2.04, –2.73, and –3.96 V, and the current ratio of the “0,” “1,” “2,” and “3” states is 1:101.78:103.47:105.36, which indicate a low possibility of read and write errors. The results represent a further step in organic high‐density data‐storage devices and will inspire the further study in this field.

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In this work, three new organic donor–acceptor small-molecules, in which bicarbazole served as the electron donor, and benzothiazole, nitryl or 1,1′-dicyanovinyl were used as the electron acceptor, were designed and synthesized in order to fabricate sandwiched memory devices. Acceptors with a variable electron-delocalized extent and electron-withdrawing strength were attached to the molecular backbone in order to investigate the effect on the devices switching behavior. The bi-n-butylcarbazole benzothiazole (BCZ-BT) based memory device exhibited volatile static random access memory (SRAM) switching behaviour, while the devices based on bi-n-butylcarbazole nitryl (BCZ-NO2) was found to exhibit stable nonvolatile write-once-read-many-times (WORM) data storage characteristics and the bi-n-butylcarbazole dicyanovinyl (BCZ-CN) device acted as rewritable flash memory with a higher ON/OFF current ratio of about 104. Therefore, tunable data storage devices synthesized by adjusting the terminal acceptor groups offer feasible guidance for the rational design of organic molecules to achieve superior memory performance.

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Ternary memory storage performances of three benzochalcogendiazole derivative based devices clearly demonstrate the effect of single atom substitution on the molecular planarity, film morphologies and device threshold voltages.