Photo-induced non-volatile VO2 phase transition for neuromorphic ultraviolet sensors

Abstract

In the quest for emerging in-sensor computing, materials that respond to optical stimuli in conjunction with non-volatile phase transition are highly desired for realizing bioinspired neuromorphic vision components. Here, we report a non-volatile multi-level control of VO2 films by oxygen stoichiometry engineering under ultraviolet irradiation. Based on the reversible regulation of VO2 films using ultraviolet irradiation and electrolyte gating, we demonstrate a proof-of-principle neuromorphic ultraviolet sensor with integrated sensing, memory, and processing functions at room temperature, and also prove its silicon compatible potential through the wafer-scale integration of a neuromorphic sensor array. The device displays linear weight update with optical writing because its metallic phase proportion increases almost linearly with the light dosage. Moreover, the artificial neural network consisting of this neuromorphic sensor can extract ultraviolet information from the surrounding environment, and significantly improve the recognition accuracy from 24% to 93%. This work provides a path to design neuromorphic sensors and will facilitate the potential applications in artificial vision systems.

Retina-inspired controllable neuromorphic vision organic sensors with ultraweak ultraviolet detection

“…It is worth mentioning that all the best value of R above 10 6 A W -1 and D * above 10 16 Jones can be achieved on different dielectric layers, and the performance of our OPTs in all aspects is compared with that reported in previous literature, as shown in Table S1, demonstrating the strong detection ability of weak light by using BTBTT6-syn-based phototransistors. Based on the ultraweak UV-light detection and interface charge trapping ability, the synaptic OPTs were further investigated for emulating light information memory and processing of the visual perception system 7 . Figure 4a showed the typical synaptic plasticity of excitatory postsynaptic current (EPSC) of the bare SiO2 device.…”

“…Neuromorphic vision sensor (NeuVS) can emulate the in-sensor computing operations of human visual perception system though integrating functions of photosensor and artificial synapse on one device 3 . This highly compact all-in-one sensor device could simplify the circuit complexity of the artificial vision system, improve the efficiency of information processing and reduce the power consumption [4][5][6][7][8] . In the retina, photoreceptor cell (PRC, i.e., cone cells) could detect light and convert them into electrical signals to stimulate biological perception processes.…”

Vertical Barrier Heterostructures for Reliable, Robust, and High‐Performance Ultraviolet Detection

“…[18,19] And high-energy UV photons can create crystal lattice defects hence long-term exposure to UV lights will cause a performance degradation of the detector. [20] Wide-band gap semiconductors like SiC, GaN, and AlGaN are expected to surmount the above problems due to their intrinsic visible-blind band gaps and high radiation hardness. [11,[21][22][23] However, heterojunction growth with high crystal quality and small interfacial stress is limited by lattice mismatch and high density of structural defects, which hinders their use.…”

Controlled Optoelectronic Response in van der Waals Heterostructures for In‐Sensor Computing

“…Toward such an elegant and efficient machine vision scheme, emerging types of optoelectronic memory devices, whose intrinsic physical properties are subject to external optical stimulation, have been suggested as a promising solution for hardware demonstration of in-sensor computing. [2,5,[10][11][12][13][14][15][16][17][18] Such optoelectronic memories can be written/erased optically and accessed electrically, offering all the benefits of the conventional machine vision technology in combination with added functionalities from the memory characteristics. [10] Beyond the plain optoelectronic memory capability that can record the optical events with intrinsic electronic state variation, [19] i.e., optical information sensing and data storage, this type of device can further act on its own as an information processor, thus allowing data processing directly within the sensor/memory unit, the so-called in-sensor computing.…”