Organic Single-Crystal Transistor with Unique Photo Responses and Its Application as Light-Stimulated Synaptic Devices

Abstract

Tremendous progress has been achieved on organic transistor-based photodetectors; however, because of the nonpositive correlation relationship between the photo/dark current ratio (P) and the gate voltage, the claimed best P, R (photoresponsivity), and D* (detectivity) can hardly be obtained simultaneously at a given gate voltage, which severely compromises the device performance. Here, a light and voltage dually gated transistor based on an organic semiconducting single crystal of 2,6-dithienylanthracene (DTAnt) is developed. Attributing to its very low on/off ratio in the dark and the remarkable increment of mobilities under illumination, this phototransistor shows good performance with a P of 3.83 × 103, R of 1.32 A W–1, and D* of 1.94 × 1012 Jones achieved simultaneously at V g = −100 V. Besides, the good reversibility and repeatability of its light-responsive behavior allows for the construction of an artificial photonic neuromorphic device with demonstrated synaptic functions, including excitatory postsynaptic current, short/long-term memory , and pair-pulse facilitation/depression.

Responsive Zwitterionic Polymers with Humidity and Voltage Dual-Switching for Multilevel Date Encryption and Anticounterfeiting

“…Reducing the RH from 60% to 20% decreases the I d by 3 orders in 6 min, though the relatively slow out-diffusion of moisture from the dielectric layer leads to residual I d and delayed response. This I d responsive rate and magnitude change outperform many reported optical switchable transistors based on photoisomers of which the responsive time and I d,sat change are 2–20 min and 10–90%, respectively, ,− and rvial many high performance phototransistors (Figure f). − Given that a 2-order of I d change is sufficient to discriminate between “on” and “off” status, coupled with the high I d responsive-rate demonstrated here, it is expected that these transistors could be readily switched with acceptable high speed by simply adjusting RH. In addition, multicycles measurement of I d at high and low RH, respectively, reveals good repeatability of such humidity-responsive behavior (Figure S13d).…”

A Camel Nose-Inspired Highly Durable Neuromorphic Humidity Sensor with Water Source Locating Capability

“…Adjusting the pulse width as well as the film pore content could easily tune the EPSC curve with a different decay rate (τ –1 ) (Figures d and S9). Generally, a higher pore content leads to a faster decay rate and vice versa. Further, a paired pulse facilitation (PPF) behavior is observed by exposing the sensor to two consecutive moisture pulses, as indicated by the EPSC increase in Figure c.…”

“…Adjusting the pulse width as well as the film pore content could easily tune the EPSC curve with a different decay rate (τ −1 ) (Figures 7d and S9). 47 Generally, a higher pore content leads to a faster decay rate and vice versa.…”

Organic Synaptic Transistors: The Evolutionary Path from Memory Cells to the Application of Artificial Neural Networks

“…Different semiconductor materials of organic synaptic devices can imitate neurons with different functions. For example, devices made of light sensitive organic semiconductor materials (pentacene, [ 67 ] 2,7‐dioctyl benzothieno[3,2‐b] benzothiophene (C 8 ‐BTBT), [ 66 ] perovskite quantum dots/conjugated polymers, [ 71 ] single crystal of 2,6‐dithienylanthracene (DTAnt), [ 72 ] and organic molecular crystals (OMCs) [ 73 ] ) often imitate visual neurons with the functions of radio transmission and digit recognition simulation. [ 51,74 ] Meanwhile, some organic–inorganic composite of photosensitive materials, such as MoS 2 /perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTCDA and CsPbBr 3 /pentacene, are also used to mimic visual neural systems [ 75,76 ] ).…”