Light Intensity‐Controlled Photoconductance Polarity Switching for Neuromorphic and Logic Applications

Abstract 2D transition metal dichalcogenide (TMD) semiconductors and their heterostructures are widely studied for their positive photoconductance properties. Recent studies further explore the reversible modulation between positive photoconductance (PPC) and negative photoconductance (NPC), enabling applications in high‐precision image recognition and bidirectional reconfigurable logic gates. However, the reversible photoconductance switching effect is commonly induced by different light wavelengths or gate voltages, which require multiple light sources or additional electronic components. Here, a photoconductance polarity switching effect is reported, induced by light intensity and duration in geometrically asymmetric p ‐type MoSe 2 devices. This effect arises from the asymmetric modulation of Schottky barrier heights due to the accumulation of photogenerated electrons at the MoSe 2 /Cr interfaces. Additionally, a photosynaptic effect is observed, likely caused by the trapping/de‐trapping of photogenerated carriers within the MoSe 2 crystal. Finally, a new type of reconfigurable logic gate with “OR” and “AND” functions is demonstrated in a single MoSe 2 device in which the light intensity and light‐on duration from a single light source are the logic gate inputs, and the polarity of the output current determines the logic gate output.