Fig. 1. (Color online) (a) Schematic diagram of 8 × 8 P3HT/N2200 based organic ambipolar optoelectronic synaptic transistor array under illumination. (b) Schematic diagram of single P3HT/N2200 transistor. (c) Molecular structures of the P3HT and N2200. (d) The schematic diagram of light assisted burn after reading. The information can be read under the assistance of light (ⅰ) and erased by removing the light (ⅱ). (e) The optical image of 8 × 8 transistor array. (f) UV−vis solution absorption spectra of the P3HT/N2200 blend film. (g) The cross-section SEM image of P3HT/N2200 polymer blend film.

Fig. 2. (Color online) (a) Schematic of the process for manufacturing P3HT/N2200 based transistor. (b)−(d) The transfer curves P3HT/N2200 based transistors with different mass ratio. (b) 1 : 1; (c) 1 : 2; (d) 1 : 3. (e)−(g) AFM images of P3HT/N2200 blend films with different mass ratio. (e) 1 : 1; (f) 1 : 2; (g) 1 : 3.

Fig. 3. (Color online) (a) I−V transfer characteristics under the variation of V_DS from 10 to 20 V. (b) I−V characteristics under the variation of V_DS from −10 to −20 V. (c) and (d) The output characteristic curves of P3HT/N2200 based FET under the dark condition. (e) EPSC induced by applying different negative V_GS pulses from −5 to −35 V, under the condition of V_DS = 15 V and base V_GS = 5 V (pulse width: 0.1 s). (f) IPSC induced by applying different positive gate pulses from 10 to 25 V, under the condition of V_DS = 15 V and base V_GS = 5 V (pulse width: 0.1 s).

Fig. 4. (Color online) (a)−(c) Transfer curves of P3HT/N2200 based FETs in the dark and under different illumination intensities with the wavelength of 365 nm (a), 520 nm (b), and 637 nm (c). (d)−(i) The PSC responses of P3HT/N2200 based transistors to light pulse with different wavelength [365 nm (d) and (g); 520 nm (e) and (h), and 637 nm (f) and (i)] under different polarity V_GS [−1 V (d)−(f); 20 V (g)−(i)].

Fig. 5. (Color online) (a)−(c) The distribution of charge carriers in the P3HT/N2200 channel under different conditions. (a) Initial state (dark condition, V_GS = 0 V); (b) negative positive gate bias state (light condition); (c) positive gate bias state (light condition). (d) Energy level diagram of the P3HT/N2200 device upon illumination. (e) and (f) KPFM images of P3HT/N2200 film upon dark (up) and illumination (down) under different V_GS. (e) V_GS = −10 V; (f) V_GS = 10 V.

Fig. 6. (Color online) (a) Device array diagram. (b) The transient current response for P3HT/N2200 transistor array with a one-to-one mapping programmed V_GS in dark, cannot read information completely. (c) The image information is encoded by various gate voltages (−1 and 20 V). (d)−(f) The evolution of the light assisted burn after reading process in full information access mode under green light. (d) Schematic of the array in full green light illumination with mask 1. (e) The transient current response for P3HT/N2200 based transistor array in the condition of light illumination, achieving information reading. (f) After light removal, the information is automatically erased. (g)−(i) The evolution of the light assisted burn after reading process in partial information access under green light with mask 2. (g) Schematic of the array in selective light illumination with mask 2. (h) The transient current response for P3HT/N2200 based transistor array in the condition of light illumination, achieving information selective reading. (i) After light removal, the information is selectively and automatically erased.