Synergistic Dimensional and Defect Engineering in Ga-Doped IGTO Nanofiber Transistors for Dual-Band Neuromorphic Vision and Optical Encryption.

Here, we report a synergistic strategy that integrates one-dimensional (1D) nanostructuring with precise Ga doping to fabricate high-performance indium-gallium-tin oxide (IGTO) nanofiber field-effect transistors (FETs). The optimized 5% Ga doping effectively suppresses oxygen vacancies (from 38.8 to 29.7%) via strong G-O bonds, enabling an excellent mobility of 2.79 cm2 V-1 s-1, a high on/off ratio of 4.15 × 107, a steep subthreshold swing of 0.50 V/dec, and remarkable bias-stress stability, thereby overcoming the classic mobility-stability trade-off in oxide semiconductors. Beyond the superior electrical characteristics, the IGTO nanofiber FETs exhibit a tunable dual-band photoresponse (340 nm UV and 430 nm visible), which successfully emulates essential synaptic behaviors, including excitatory postsynaptic currents, paired-pulse facilitation, and short-term to long-term memory transitions. Capitalizing on this wavelength-selective responsivity, we further demonstrate a proof-of-concept optical encryption-decryption system for MNIST digits, achieving a recognition accuracy of 95%. This work establishes a "dimensional control, precise doping, and defect engineering" paradigm, showcasing the great potential of IGTO nanofibers as a versatile platform for neuromorphic vision systems and secure optoelectronic applications.