Comprehensive understanding of the structure-stacking property correlation to achieve high-performance ternary data-storage devices

Abstract

The previously proposed “charge-trap” mechanism guided us to design a number of ternary small molecules and to construct the “structure–property” relationship. However, there are still a few molecules that cannot reflect the ternary properties, which is thought to be stacking related in films since intermolecular stacking has been verified to significantly affect the device performance. Thus, how to design a tailor-made molecular system with the same electron-acceptors but different molecular stacking modes is thought to be a perfect strategy to construct the “structure-stacking property” relationship. In this work, two isomers (meta-substituted molecule m-BQBTZ and para-substituted molecule p-BQBTZ) were rationally synthesized to consider the bridge conjugation effect on the intermolecular stacking styles and the memory properties. The comprehensive theoretical and experimental results revealed that p-BQBTZ formed a preferred face-to-face structured slip-stacked packing in the film state, making the p-BQBTZ based memory devices exhibit ternary non-volatile ternary WORM (write-once-read-many times) memory performance. This work demonstrates that the molecular stacking effect is an important factor that is equal to the structural foundry, which should be carefully considered in future organic memory devices.