The extraordinary optoelectronic properties and continued commercialization of GaN enable it a promising component for neuromorphic visual system (NVS). However, typical GaN‐based optoelectronic devices demonstrated to data only show temporary and unidirectional photoresponse in ultraviolet region, which is an insurmountable obstacle for construction of NVS in practical applications. Herein, an ultrasensitive visual sensor with phototransistor architecture consisting of AlGaN/GaN high‐electron‐mobility‐transistor (HEMT) and two‐dimensional Ruddlesden–Popper organic–inorganic halide perovskite (2D OIHP) is reported. Utilizing the significant variation in activation energy for ion transport in 2D OIHP (from 1.3 eV under dark to 0.4 eV under illumination), the sensor can efficiently perceive and storage optical information in ultraviolet–visible region. Meanwhile, the photo‐enhanced field‐effect mechanism in the depletion‐mode HEMT enables gate‐tunable negative and positive photoresponse, where some typical optoelectronic synaptic functions including inhibitory and excitatory postsynaptic current as well as paired‐pulse facilitation are demonstrated. More importantly, a NVS based on the proposed visual sensor array is constructed for achieving neuromorphic visual preprocessing with an improved color image recognition rate of 100%.

A single device with switchable functions is highly attractive to the growing demands of complex optoelectronics. However, most of the currently reported devices either exhibit a lack of multifunction operation or require complex electrode configurations with limited performances. Here, a new concept of a functionalized‐black phosphorus (f‐BP)/MoS2 heterojunction is proposed, which enables the coexistence of an optoelectronic memory and a detector in a single device. The oxidation‐induced artificial‐traps on the BP surface result in a gate‐modulated photogating effect, so that the device can be freely switched between memory and detector by simply changing the back‐gate voltage. In the memory model, the device has an ultra‐long storage time (10 years), an ultra‐high on/off ratio (3.5 × 107), and outstanding multi‐bit storage (≈90 states), while in the detector model, the device still exhibits a fast response (130/260 µs), an impressive responsivity (22.2 A W−1), and self‐driven broadband detection (ultraviolet to near‐infrared). Most importantly, the highly anisotropic BP enables fast NIR polarization resolution with a maximum polarization ratio of 6.98 at 1064 nm.

Nonvolatile optoelectronic memories based on organic–inorganic hybrid perovskites have appeared as powerful candidates for next-generation soft electronics. Here, ambipolar SnO transistor-based nonvolatile memories with multibit memory behavior (11 storage states, 120 nC state–1) and ultralong retention time (>105 s) are demonstrated for which an Al2O3/two-dimensional Ruddlesden–Popper perovskite (2D PVK) heterostructure dielectric architecture is employed. The unique storage features are attributed to suppressed gate leakage by Al2O3 layer and hopping-like ionic transport in 2D PVK with varying activation energy under different light intensities. The photoinduced field-effect mechanism enables top-gated transistor operation under illumination, which would not be achieved under dark. As a result, the device exhibits remarkable photoresponsive characteristics, including ultrahigh specific detectivity (2.7 × 1015 Jones) and broadband spectrum distinction capacity (375–1064 nm). This study offers valuable insight on the PVK-based dielectric engineering for information storage and paves the way toward multilevel broadband-response optoelectronic memories.

With the progress of both photonics and electronics, optoelectronic synapses are considered potential candidates to challenge the von Neumann bottleneck and the field of visual bionics in the era of big data. They are also regarded as the basis for integrated artificial neural networks (ANNs) owing to their flexible optoelectronic tunable properties such as high bandwidth, low power consumption, and high-density integration. Over the recent years, following the emergence of metal halide perovskite (MHP) materials possessing fascinating optoelectronic properties, novel MHP-based optoelectronic synaptic devices have been exploited for numerous applications ranging from artificial vision systems (AVSs) to neuromorphic computing. Herein, we briefly review the application prospects and current status of MHP-based optoelectronic synapses, discuss the basic synaptic behaviors capable of being implemented, and assess their feasibility to mimic biological synapses. Then, we focus on the two-terminal optoelectronic synaptic memristors and three-terminal transistor synaptic phototransistors (SPTs), the two essential apparatus structures for optoelectronic synapses, expounding their basic features and operating mechanisms. Finally, we summarize the recent applications of optoelectronic synapses in neuromorphic systems, including neuromorphic computing, high-order learning behaviors, and neuromorphic vision systems, outlining their potential opportunities and future development directions as neuromorphic devices in the field of artificial intelligence (AI).

Non‐destructive and reversible modulations of polarity and carrier concentration in transistors are essential for complementary devices. The fabricated multi‐gated WSe2 devices obtain dynamic electrostatic field induced electrically configurable functions and demonstrate as diode with high rectification ratio of 4.1 × 105, as well as n‐ and p‐type inverter with voltage gain of 19.9 and 12.1, respectively. Benefiting from the continuous band alignment induced modulation of channel underneath the dual gates, the devices exhibit high‐performance photodetection in wide spectral range. The devices yield high photo‐responsivity (5.16 A W−1) and large Ilight/Idark ratio (1 × 105). Besides, the local gate fields accelerate the separation of photo‐induced carriers, leading to fast response without persistent current. This strategy takes the advantage of the simplified design and continues to deliver integrated circuits with high density. The superior electrical and photodetection characteristics exhibit great potency in the domain of future optoelectronics.