Photonic Synapses: Retina‐Inspired Carbon Nitride‐Based Photonic Synapses for Selective Detection of UV Light (Adv. Mater. 11/2020)

Abstract

In article number 1906899, to selectively detect and process UV‐exposure information, Sungjin Park, Tae‐Woo Lee, and co‐workers, demonstrate artificial photonic synapses that emulate the functions of a retina by using a UV‐responsive 2D carbon nitride layer in a floating‐gate transistor. These photonic synapses could expand the human visual sense beyond visible light and be applicable to healthcare devices.

Deep Ultraviolet Light Stimulated Synaptic Transistors Based on Poly(3-hexylthiophene) Ultrathin Films

“…So far, many types of devices for emulating synaptic behavior have been reported in the literature, including tri/multiterminal transistors and two-terminal resistance switching memories. − In contrast to two-terminal devices, the transistor-based tri/multiterminal devices can both write and read information simultaneously. − In addition, the application of external stimuli such as light and voltage can be easily converted into electrical signals in the transistor’s configuration by designing the structure of the device and selecting the appropriate materials. ,− Among them, the option of optical stimulation offers significant advantages of high bandwidth, ultrafast signal transmission, and robustness, which are quite crucial parameters for the practical application of artificial synaptic devices . Most of the current research on light-stimulated synaptic devices is focused on the enforcement of ultraviolet A (UVA), ultraviolet B (UVB) (ultraviolet radiation is generally divided into three subregions by wavelength: UVA (320–400 nm), UVB (280–320 nm), and ultraviolet C (200–280 nm)), visible, and near-infrared light. ,− However, by considering the needs for enhanced military detection, biological and medical analysis, flame detectors, etc., the research on the fabrication of deep ultraviolet (DUV) light stimulation devices has received a great deal of attention. − It is interesting to notice that the detection and memory effects induced by DUV light on a single device have been achieved. − Recently, our group reported a novel nonvolatile solar-blind DUV optoelectronic memory device composed of an organic field-effect transistor (OFET) with multilevel memory behavior and rewriting capability, whereas the memory has a high selectivity for DUV at 254 nm . The above work also demonstrated a very good selective detection and memory effect on DUV light.…”

Vertical Channel Inorganic/Organic Hybrid Electrochemical Phototransistors with Ultrahigh Responsivity and Fast Response Speed

“…However, OFETs often possess a low transconductance value with only dozens of μS because of their low device capacitance, leading to the limited improvement in the photoelectric performance of OPTs . In addition, OPTs based on OFETs often require excessively high operating voltage (>10 V) for obtaining higher photoelectric performance, which gives rise to large power consumption and leads to problems in heat dissipation and thereby they are difficult to be integrated into wearable and mobile electronic devices. ,− Therefore, it is highly desirable to resolve the challenges of OFET-based OPTs through exploring new device configurations for constructing highly photosensitive and low-voltage-driven OPTs.…”

Flexible Optoelectronic Synapses Based on Conjugated Polymer Blends for Ultra Broadband Spectrum Light Perception

“…Efficient photoelectric conversion under external light stimulation is one of the necessary conditions to achieve broad-spectrum biomimetic optoelectronic synapse simulation. , Energy band and level engineering is an effective strategy. Functional applications can be achieved through the specific selection of semiconductor materials . Conjugated polymer materials offer significant advantages in absorption spectrum broadening, energy level design, and flexible electronic preparation. − Therefore, the development of polymer semiconductor flexible neuromorphic devices with broad-spectrum sensing for multifunctional applications will be of great significance.…”

“…Functional applications can be achieved through the specific selection of semiconductor materials. 23 offer significant advantages in absorption spectrum broadening, energy level design, and flexible electronic preparation. 24−26 Therefore, the development of polymer semiconductor flexible neuromorphic devices with broad-spectrum sensing for multifunctional applications will be of great significance.…”