Optoelectronic Mesoporous Titania Memristor with Light‐Modulation by Laser Pointer

Abstract Here, optoelectronic synaptic device based on thin film mesoporous titania (meso‐TiO 2 ) is demonstrated as sensing active layer under illumination of low power laser pointers (532 nm or 632 nm), which could modulate weight change of input signal under the light‐illumination and electrical‐bias sequentially. Moreover, through both photonic and electronic co‐modulation of input signal on the aluminum/meso‐TiO 2 /indium tin oxide (ITO) device array, multiple hand‐writings of numerical letters of “3” and “5” by laser pointer could be identified, stored, and erased. The laser pointer drawn letter images were self‐adaptively preprocessed and memorized as photosynaptic perception concept with the visual neuromorphic 28 × 28 array. Moreover, the photosynaptic devices were demonstrated to possess self‐rectifying and three different meso‐TiO 2 device's formats of crossbar, cap, and lateral electrode structures along with the various metal materials for top and bottom electrodes. In addition, the current–voltage ( I–V ) characteristics with series of photonic potentiation by lase pointer could show excitatory postsynaptic current (EPSC) behavior as well. In addition, thermal protocol of erase for the laser induced memory was examined, which could reset the adaptively perceived and memorized image under laser illumination. Accordingly, the dual modulation of photo‐synaptic meso‐TiO 2 array can open initial step for artificial visual platform for image acquisition and preprocessing.