Photogating in Suspended InAs Nanowire Field Effect Transistors for Neuromorphic Applications

ABSTRACT Suspended indium arsenide (InAs) nanowires offer a unique platform for studying surface‐driven transport phenomena due to their high surface‐to‐volume ratio and the absence of dielectric interfaces. In this work, we investigate the role of surface states in InAs nanowire field‐effect transistors. Electrical characterization reveals a high electron mobility of ≈1500 cm 2 V −1 s −1 , alongside a subthreshold swing of 1.49 V dec −1 , indicating a reduced gate efficiency caused by surface traps. Temperature‐dependent analysis yields activation energies of ∼100 meV, confirming the dominant influence of shallow trap states on both threshold voltage and subthreshold slope. Under pulsed optical excitation, the devices exhibit persistent negative photoconductivity and gate‐tunable hysteresis. The on/off current ratio exceeds 10 5 at 200 K. These effects are attributed to a photogating mechanism controlled by the interplay between gate voltage and photoinduced trap occupation. The demonstrated ability to modulate long and short‐term memory behavior through optical and electrical stimuli highlights the potential of these nanowire devices for neuromorphic applications.