Mixed-Halide Perovskite Memristors with Gate-Tunable Functions Operating at Low-Switching Electric Fields

Abstract

Crossbar circuits based on two terminal (2T) memristors typically require an additional unit such as a transistor for individual node selection. A memristive device with gate-tunable synaptic functionalities will not only integrate selection functionality at the cell level but can also lead to enriched on-demand learning schemes. Here, a three-terminal (3T) mixed-halide perovskite memristive device with gate-tunable synaptic functions operating at low potentials is demonstrated. The device operation is controlled by both the drain (VD) and gate (VG) potentials, with an extended endurance of >2000 cycles and a state retention of >5000 s. Applying a voltage (Vset) of 20 V across the 50 µm channel switches its conductance from a high-resistance state (HRS) to a low-resistance state (LRS). A memristive switching mechanism is proposed that is supported by current injection models through a Schottky barrier and Kelvin probe force microscopy data. The simultaneous application of a VG potential is found to further modulate the channel conductance and reduce the operating Vset to 2 V, thus requiring a low electric field of 400 V cm−1, which is by a factor of 50× less compared to state-of-the-art literature reports. Gate-tunable retention, endurance, and synaptic functionalities are demonstrated, further highlighting the beneficial effect of VG on device operation.