A Wavelength‐Tunable Multi‐Functional Transistor with Visible‐Light Detection and Inverse Photomemory for Logic Gate and Retina Emulation

Abstract The multi‐functional phototransistor is essential for the realization of highly‐integrated multi‐functional electronics. Herein, inverse photomemory is discovered from the organic phototransistor based on dinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene (DNTT)/diarylethene (DAE) bilayer structure. With the incorporation of the photoactive DAE dielectric layer, the integration of high‐performance photodetection and photomemory in one device is realized. The function of the device can be switched by changing the wavelength of the incident light. The devices exhibit positive photosensing performances under the stimulation of 450 nm monochromatic light, can be switched to inverse photomemory transistors under the stimulation of 365 nm monochromatic light, and recover to the pristine state when applying a positive gate voltage and 600 nm illumination. The I 450 / I dark ratio of positive photosensing and the I dark / I 365 ratio of inverse photomemory are high up to the order of 10 6 and 10 7 , respectively. In addition, the photonic logic gate and the retina emulation have been successfully demonstrated. In addition, the device can be operated as a light‐stimulated synaptic transistor. The typical synaptic behaviors (excitatory postsynaptic current, paired pulse facilitation, memory, and learning behaviors) have been successfully demonstrated. The development of multi‐functionalized phototransistors provides a promising configuration for multi‐functional and highly‐integrated systems.