Regionally controlled ion-doping of organic electrochemical transistors for computing-memory co-integrated neuromorphic systems

Abstract Organic electrochemical transistors (OECTs), endued with processing and memory functionalities, present a remarkable potential for neuromorphic electronics. However, integrating processing and memory cores for neuromorphic systems is complicated by heterogeneous material compatibility and device architecture constraints. Here, we demonstrate a versatile regionally controlled ion-doping strategy for modulating the operational mode of OECTs between high-performance computing and non-volatile memory, without varying the materials or operating conditions. The key to this method is the use of inkjet-printed electrolytes with programmable 3D architectures, which can be precisely deposited onto the OECT channel, achieving a tunable thickness ranging from 100 nm to several tens of micrometers. By engineering the electrolyte’s spatial structure, we demonstrate two complementary OECT configurations: ion-rich OECTs with multilayer electrolytes achieve high stimulus-resolution capability of 1 ms for dynamic computation, and ion-deficient OECTs with single-layer electrolytes establish stable ion-trapping memristive states (300 s retention). Moreover, the integration of ion-rich and ion-deficient OECTs enables a neuromorphic circuit capable of simultaneous encoding and storage of alphanumeric information. This study presents a simple yet effective strategy that overcomes material compatibility constraints and simplifies circuit design, paving the way for highly integrated neuromorphic systems based on OECTs.