A Novel Indium Gallium Zinc Oxide Channel‐Based Electrochemical Field Effect Transistor for Physical Reservoir Computing

With the growing demand for efficient data analysis in the era of big data and artificial intelligence, the limitations of traditional von Neumann computing systems, especially in parallel processing, have become evident. Reservoir computing (RC), an energy‐efficient computing paradigm that leverages fixed weights and trains only the output layer, has emerged as a promising solution. Physical reservoir computing (PRC), which implements RC in hardware, enables real‐time and large‐scale data processing but faces challenges, such as process variability, material degradation, and limited complementary metal‐oxide‐semiconductor (CMOS) compatibility. This study introduces a novel PRC device based on an electrochemical field‐effect transistor (EcFET) with an indium gallium zinc oxide (IGZO) channel. The EcFET controls oxygen vacancies, which act as n‐type dopants, by injecting and extracting oxygen ions through electrochemical redox reactions in the channel. By applying an electric field to the gate electrode, the threshold voltage of the channel is controlled, enabling conductance modulation. With its low ion diffusivity, the IGZO channel provides short‐term memory characteristics and excellent performance. The proposed device exhibits a time constant of ≈300 ms, durability over ≈10 4 cycles, cell variability below 10%, and test accuracy of 94.29%. These findings demonstrate the potential of IGZO‐based EcFETs for next‐generation energy‐efficient PRC.