Light polarization as a control knob for resistive switching in chiral perovskite memory

초록

Resistive random-access memory (RRAM) based on metal-halide perovskites has attracted significant interest for neuromorphic and in-memory computing applications owing to its simple structure and tunable material properties. However, practical implementation is limited by stochastic filament formation and the lack of effective control parameters beyond electrical bias and light intensity. Here, we introduce light polarization as an independent control variable for resistive switching using a chiral perovskite RRAM device. Owing to the intrinsic circular dichroism of the chiral perovskite, right- and left-circularly polarized light (RCP and LCP) generate different photocarrier populations under identical illumination intensity, enabling deterministic modulation of switching behavior. As a result, the set voltage (Vset) is reduced from 0.15 V in the dark to 0.10 V and 0.05 V under RCP and LCP, respectively, accompanied by improved switching uniformity. Conduction mechanism analysis reveals that polarization-dependent photocarrier generation induces a transition from interfacelimited to bulk-dominated transport, thereby stabilizing filament nucleation. In addition, the incorporation of bulky chiral ligands, which enhances chirality, leads to enlarged interlayer spacing that facilitates uniform Ag ion infiltration and suppresses stochastic filament formation. Finally, polarization-modulated synaptic characteristics are demonstrated, and artificial neural network simulations show enhanced learning performance. These results demonstrate that polarization-driven control of resistive switching can be effectively reinforced by structural engineering, establish light polarization as a new control knob for resistive switching, and provide a viable pathway toward multifunctional memory and neuromorphic applications.

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