Artificial neural network with broad application prospect has attracted particular attention due to the promise of solving the memory wall bottleneck. The neural devices that mix light and electricity provide more degrees of freedom for the design of artificial neural network, but they still do not get rid of the shackles that the response signal needs circuit to transmission. The exploration of all-optical neural devices (optical signal input and output) is expected to solve this problem. Here, an all-optical synaptic device simply based on a long-afterglow material is reported. The optical properties of the all-optical synaptic device are similar to the responses in biological synapses. Unique image displays and memory functions can be achieved by combining all-optical synaptic arrays with synaptic memory behavior. Furthermore, the optical summation of all-optical synaptic array pixels can be completed by combining the focusing characteristics of convex lens, which realizes the photon transmission after preprocessing multiple input signals. Particularly, the simple single-layer structure of all-optical synapses with polydimethylsiloxane (PDMS) as the carrier has high plasticity and is expected to achieve large-scale preparation. This work enriches the diversity of artificial synapses and shows the huge development potential of photoelectric artificial neural networks.

Multi-sensory neuromorphic devices (MND) have broad potential in overcoming the structural bottleneck of von Neumann in the era of big data. However, the current multisensory artificial neuromorphic system is mainly based on unitary nonvolatile memory or volatile synaptic devices without intrinsic thermal sensitivity, which limits the range of biological multisensory perception and the flexibility and computational efficiency of the neural morphological computing system. Here, a temperature-dependent memory/synaptic hybrid artificial neuromorphic device based on floating gate phototransistors (FGT) is fabricated. The CsPbBr₃/TiO₂ core–shell nanocrystals (NCs) prepared by in-situ pre-protection low-temperature solvothermal method were used as the photosensitive layer. The device exhibits remarkable multi-level visual memory with a large memory window of 59.6 V at room temperature. Surprisingly, when the temperature varies from 20 to 120 °C back and forth, the device can switch between nonvolatile memory and volatile synaptic device with reconfigurable and reversible behaviors, which contributes to the efficient visual/thermal fusion perception. This work expands the sensory range of multisensory devices and promotes the development of memory and neuromorphic devices based on organic field-effect transistors (OFET).

Driven by important megatrends such as cloud computing, artificial intelligence, and the Internet of Things, as a device used to store programs and data in computing systems, memory is struggling to catch up with the explosive growth of data and bandwidth requirements in the system. However, the "storage wall" between non-volatile memory and volatile memory retards the further improvement of modern memory computing systems. Herein, a quasi-volatile transistor memory based on organic polymer/perovskite quantum dot blend was fabricated using the vertical transistor configuration. Contributing to vertical structure and appropriate doping ratio of blend film, the quasi-volatile memory device displayed 1, 560 times longer data retention time (> 100 s) with respect to the dynamic random access memory and fast data programming speed (20 μs) in which was far more quickly than that of other organic non-volatile memories to fill the gap between volatile and non-volatile memories. Moreover, the device retention characteristics could be further promoted under the photoelectric synergistic stimulation, which also provided the possibility to reduce electric writing condition. Furthermore, the quasi-volatile memory device showed good electrical performance under bending conditions. This work provides a simple solution to fabricate multi-level quasi-volatile memory, which opens up a whole new avenue of "universal memory" and lays a solid foundation for low power and flexible random access memory devices.