Optoelectronic memory with suspended InAs nanowire field effect transistor

We report the fabrication and characterization of suspended InAs nanowire field-effect transistors (FETs) for optoelectronic memory applications. The devices were realized by depositing InAs nanowires onto a polymethyl methacrylate (PMMA) sacrificial layer, followed by metal contact definition and PMMA removal to achieve a fully suspended architecture. Electrical measurements under high vacuum revealed n-type transistor behavior with good gate modulation and Ohmic contacts. Under laser illumination, the devices exhibited both positive and negative photoconductivity, depending on the gate bias, due to the interaction between photogenerated carriers and surface trap states. By exploiting the hysteretic transfer characteristics and the optical response, we demonstrated memory operation controlled by two independent variables: gate voltage and illumination condition. The device showed well-separated and stable current levels corresponding to different write-read-erase states, highlighting its potential as a multifunctional optoelectronic memory for future nanoelectronic circuits.