Resistive switching performance and mechanisms in Sb-doped perovskite-poly(9-vinylcarbazole) composite memristors

A composite material of perovskite and poly(N-vinylcarbazole) (PVK) is investigated as the resistive switching (RS) functional layer to suppress the interference of AgIx on RS performance, while low-toxicity Cs3Cu2I5:Sb is employed to replace conventional lead-based perovskites to reduce harm to the human body and environment. With the mass ratio regulation of Cs3Cu2I5:Sb in the composite, the electrical characteristics, flexible storage potential, and corresponding RS mechanism are studied systematically. The devices exhibit promising bipolar RS behavior with low set voltage (0.5–0.8 V), high on/off ratio (≈ 103), stable cycling endurance (approaching 800 cycles), and long retention time (over 104 s). Meanwhile, multilevel storage capability is achieved by modulating the compliance current (ICC). Furthermore, flexible devices with the structure of Ag/Cs3Cu2I5:Sb@PVK/ITO/PET demonstrate remarkable mechanical stability during 1000 bending cycles under various bending angles. Through the study of the device mechanism, it is concluded that the RS performance is jointly influenced by Ag electrode and iodine vacancies (VIs). The results suggest that copper-based perovskite has great potential for enhancing performance and stability of memristors.