A MOF-embedded multifunctional dielectric layer for an energy-efficient organic memtransistor and brain-inspired computing

Abstract

The development of energy-efficient neuromorphic devices has driven interest in alternative computing beyond traditional von Neumann architectures, as they emulate brain-like functionalities by integrating parallel logic and memory operations. Recent advances in neuromorphic synaptic devices have enabled applications in artificial vision systems, neuroprosthetics, and artificial olfaction. A key remaining challenge is novel material engineering for efficient charge trapping to enhance memory retention. This work demonstrates the potential of a multifunctional hybrid dielectric incorporating a metal–organic framework, namely a zeolitic imidazolate framework (ZIF67), for application in both two-terminal and three-terminal memory devices. In two-terminal Al/PMMA-ZIF67/Al devices, ZIF67 enabled non-volatile resistive switching with a high ON/OFF current ratio (∼10⁵) and set/reset voltages >2 V and −3.5 V, confirming its viability for low-power memory applications. The hybrid dielectric also supports the fabrication of low-voltage organic semiconductor-based synaptic transistors. Further, the transistor exhibits gate sweep delay-dependent hysteresis behaviour, indicative of slow charge trapping, which is crucial for memory retention. The devices also emulate key biological synaptic functions, such as spike-duration-dependent plasticity (SDDP) and spike-rate-dependent plasticity (SRDP), where excitatory post-synaptic current (EPSC) varied systematically with pulse duration and frequency. The SDDP and SRDP gain confirm synaptic plasticity and mimicry of neural behaviour. Integrating ZIF67 into PMMA offers a scalable, solution-processable, low-cost dielectric engineering strategy for a neuromorphic memtransistor.