Interface Barrier-Modulated Neuromorphic Behavior in Mo/CdIn₂S₄/ZnO–Al Structures Based on Metastable Defects

Neuromorphic computing is an increasingly accelerating research field that still faces several hardware challenges, thus driving materials science research. This contribution presents prototype neuromorphic devices based on cadmium–indium sulfide (CdIn2S4). We have found that the compound, previously studied in photocatalysis and photovoltaics, has yet-to-be-explored memristive properties. We manufactured a series of devices with varying stoichiometry and unveiled their switching and neuromorphic behavior. Our measurements indicate that barriers on the CdIn2S4 interfaces and native CdIn2S4 metastable defects control the behavior of the devices. Due to its compelling optoelectronic properties, CdIn2S4 creates vast opportunities to use it as an active layer for optically controlled neuromorphic devices. We propose a disparate switching mechanism based on metastable defects that could be utilized in neuromorphic device technology.