Optoelectronic Synapses and Photodetectors Based on Organic Semiconductor/Halide Perovskite Heterojunctions: Materials, Devices, and Applications

Abstract

Both photodetectors (PDs) and optoelectronic synaptic devices (OSDs) are optoelectronic devices converting light signals into electrical responses. Optoelectronic devices based on organic semiconductors and halide perovskites have aroused tremendous research interest owing to their exceptional optical/electrical characteristics and low‐cost processability. The heterojunction formed between organic semiconductors and halide perovskites can modify the exciton dissociation/recombination efficiency and modulate the charge‐trapping effect. Consequently, organic semiconductor/halide perovskite heterojunctions can endow PDs and OSDs with high photo responsivity and the ability to simulate synaptic functions respectively, making them appropriate for the development of energy‐efficient artificial visual systems with sensory and recognition functions. This article summarizes the recent advances in this research field. The physical/chemical properties and preparation methods of organic semiconductor/halide perovskite heterojunctions are briefly introduced. Then the development of PDs and OSDs based on organic semiconductor/halide perovskite heterojunctions, as well as their innovative applications, are systematically presented. Finally, some prospective challenges and probable strategies for the future development of optoelectronic devices based on organic semiconductor/halide perovskite heterojunctions are discussed.

Reservoir Computing Based on Oxygen-Vacancy-Mediated X-ray Optical Synaptic Device for Medical CT Bone Diagnosis

“…Compared with electrical synaptic devices, optical synaptic devices have the function of light perception, so they can be better used for neuromorphic computation of visual perception with the advantages of a more simple-structured system. After optical synaptic devices were proposed, optical synaptic devices for various light wavelengths have attracted the interest of scholars, and two-dimensional materials, chalcogenides, and oxides have been widely studied and cited as optical synaptic devices for different application scenarios. ,− However, due to the high requirements of X-ray synapses on materials and devices, that is, the irradiation resistance of material and high gain of a device with light-induced memory-like behavior, current synaptic devices are mainly concentrated in visible light. As a result, building X-ray synaptic devices becomes a big challenge .…”

Introducing Chiro-optical Activities in Photonic Synapses for Neuromorphic Computing and In-Memory Logic Operations

“…With the inevitable advent of artificial intelligence that has caused a need for enormous data, conventional computers based on von Neumann architecture are facing severe challenges owing to the separation of the memory and the processor units. , Brain-like neuromorphic computers based on synaptic devices have thereby been proposed. − The concept of the brain-inspired computing system relies on resistive switching and an associated memory phenomenon. In this direction, a range of materials, such as metal oxides, organic semiconductors, phase change materials, perovskites, ,− 2D materials, − etc., are being considered. As device structures, two and three terminal device geometries in the form of memristors, ,, and field-effect transistors, , respectively, have been studied to successfully emulate the diverse synaptic functions of the human brain.…”

“…The photonic synaptic devices, on the other hand, involve optical signal(s) in the synaptic processes. The synapses emulate the human visual system of signal-sensing and processing by the retina and image recognition toward the evolution of optical wireless communications . The devices, which are based on optoelectronic memristors, can directly sense the optical signals and process the light information to serve as artificial optical synapses .…”

Organic High‐Temperature Synaptic Phototransistors for Energy‐Efficient Neuromorphic Computing

“…[6,7] As one type of potential component unit for constructing ANNs, artificial synapses with distinctive performance have recently gained growing interest in information technology and medical health. [8][9][10][11][12][13][14][15] As artificial intelligence replaces human labor and progressively enters human life, more and more intelligent applications will involve high-temperature scenarios, which poses a challenge to the heat resistance of artificial synaptic devices. [16] Specifically, biomedical electronic devices integrated into ANNs for clinical use should withstand sterilization conditions necessary to prevent infection at the temperature above 121°C.…”