Multispectral Ferroelectric Optoelectronic Synapses with Polarization‐Controlled Memory Capability for Brain‐Inspired Visual Processing

ABSTRACT Artificial visual systems inspired by the human visual system are gaining significant attention for their capacity to efficiently process vast visual data in neuromorphic architectures. Ferroelectric‐based optoelectronic transistors with their ability to control photoconductance decay via the polarization, are particularly suited for emulating synaptic behaviors such as short‐term and long‐term plasticity. However, most reported devices are limited to narrow spectral responses with limited focus on the visible spectrum. Here, we present a visible‐light‐responsive optoelectronic synaptic transistor based on indium gallium zinc oxide (IGZO) field‐effect transistors using a ferroelectric Zr‐doped HfO 2 (HZO) gate dielectric. The device exhibits tunable conductance under red, green, and blue light illumination, replicating both sensing and synaptic learning functions. Furthermore, by manipulating the HZO polarization state via gate voltage, we achieve dynamic control over the decay rate and retention of photocurrent, enabling transitions between short‐term and long‐term plasticity. Finally, logic operations such as “AND” and “OR” are also demonstrated using dual‐wavelength optical inputs. These findings suggest the device's strong potential as a multifunctional platform for integrated artificial visual systems.