Boosting the Dopant Accommodation in Charge-Transfer Supramolecular Electrets Using Carbohydrate Block Copolymers in Phototransistor Memory.

Charge-transfer (CT)-based supramolecular systems have attracted considerable interest as electret materials for organic memory devices. However, uncontrolled dopant distribution, limited host-guest compatibility, and the formation of leakage pathways often compromise their morphological stability and memory performance. In this work, carbohydrate-based block copolymers (BCPs), maltotriose-block-poly-(1-pyrenemethyl methacrylate) (PPy) and maltotriose-block-poly-(benzyl methacrylate) (PB), are employed as supramolecular hosts for incorporating the electron acceptor F4-TCNQ, forming a series of supramolecular electret systems for organic phototransistor memory applications. Photoluminescence and time-resolved photoluminescence characterizations confirm efficient photoinduced intermolecular CT interactions in the PPy/F4-TCNQ systems, as evidenced by significant fluorescence quenching and a shortened excited-state lifetime. More importantly, solvent-vapor annealing induces supramolecular reorganization within the electret layer, thereby effectively regulating dopant distribution and reducing leakage pathways. Meanwhile, optical, morphological, and surface-energy analyses further reveal that the maltotriose carbohydrate block plays a critical role in suppressing channel interference and stabilizing the supramolecular architecture. As a result, the optimized phototransistor memory exhibits a high photosensitivity of 1.27 × 107 and a memory ratio of 1.61 × 106. Furthermore, reliable memory operation is maintained under low-light-intensity (0.01 mW cm-2) and low-operating-voltage (-0.1 V) conditions. These findings demonstrate that carbohydrate-based BCPs provide an effective platform for integrating CT supramolecular interactions with controllable dopant organization, offering a versatile molecular design strategy for developing high-performance organic photomemory devices.