An ideal anti-counterfeiting technique has to be inexpensive, mass-producible, nondestructive, unclonable and convenient for authentication. Although many anti-counterfeiting technologies have been ...developed, very few of them fulfill all the above requirements. Here we report a non-destructive, inkjet-printable, artificial intelligence (AI)-decodable and unclonable security label. The stochastic pinning points at the three-phase contact line of the ink droplets is crucial for the successful inkjet printing of the unclonable security labels. Upon the solvent evaporation, the three-phase contact lines are pinned around the pinning points, where the quantum dots in the ink droplets deposited on, forming physically unclonable flower-like patterns. By utilizing the RGB emission quantum dots, full-color fluorescence security labels can be produced. A convenient and reliable AI-based authentication strategy is developed, allowing for the fast authentication of the covert, unclonable flower-like dot patterns with different sharpness, brightness, rotations, amplifications and the mixture of these parameters.
Flexible floating‐gate organic transistor memory (FGOTM) is a potential candidate for emerging memory technologies. Unfortunately, conventional planar FGOTM suffers from weak driving ability and ...insufficient mechanical flexibility, which limits its commercial application. In this work, a novel flexible vertical FGOTM (VFGOTM) is reported. Benefitting from new vertical architecture, VFGOTM provides ultrashort channel length to afford an extremely high current density. Meanwhile, VFGOTM devices exhibit excellent memory performance and outstanding retention property. The memory properties of VFGOTM devices are comparable or even better than traditional planar FGOTM and much better than the reported organic nonvolatile memory with vertical transistor structures. More importantly, organic nonvolatile memory with vertical transistor structures is investigated for the first time on a flexible substrate. The results show that VFGOTM architecture allows vertical current flow across the channel layer to effectively eliminate the effect of mechanical bending during current transport, which significantly improves the mechanical stability of the flexible VFGOTM. Hence, with a combination of excellent driving ability, memory performance, and mechanical stability, VFGOTM devices meet the practical requirements for high performance memory applications, which have great potential for the application in a wide range of flexible and wearable electronics.
A novel vertical‐architecture, floating‐gate organic transistor memory fabricated on a flexible substrate is reported. The unique vertical architecture enables memory devices with ultrashort channel length, which provides a large current density (excellent driving ability), fast operation, and mechanical stability, showing great potential for the application in a wide range of flexible and wearable electronic applications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
With the ever-growing demand for a greater number of pixels, next-generation displays have challenging requirements for resolution as well as colour gamut. Here, to meet this need, quantum-dot ...light-emitting diodes (QLEDs) with an ultrahigh pixel resolution of 9,072–25,400 pixels per inch are realized via transfer printing combined with the Langmuir–Blodgett film technology. To reduce the leakage current of the devices, a honeycomb-patterned layer of wide-bandgap quantum dots is embedded between the light-emitting quantum-dot pixels as a non-emitting charge barrier layer. Red and green QLEDs are demonstrated. Notably, the red devices achieve a brightness of up to 262,400 cd m−2 at an applied voltage of 8 V and a peak external quantum efficiency of 14.72%. This work provides a promising way for achieving ultrahigh-resolution QLED devices with high performance.The demonstration of high-resolution quantum-dot light-emitting diodes by transfer printing could prove useful for next-generation displays.
The mimicking of classical conditioning, including acquisition, extinction, recovery, and generalization, can be efficiently achieved by using a single flexible memristor. In particular, the ...experiment of Pavlov's dog is successfully demonstrated. This demonstration paves the way for reproducing advanced neural processes and provides a frontier approach to the design of artificial‐intelligence systems with dramatically reduced complexity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Realizing multi-modal information recognition tasks which can process external information efficiently and comprehensively is an urgent requirement in the field of artificial intelligence. However, ...it remains a challenge to achieve simple structure and high-performance multi-modal recognition demonstrations owing to the complex execution module and separation of memory processing based on the traditional complementary metal oxide semiconductor (CMOS) architecture. Here, we propose an efficient sensory memory processing system (SMPS), which can process sensory information and generate synapse-like and multi-wavelength light-emitting output, realizing diversified utilization of light in information processing and multi-modal information recognition. The SMPS exhibits strong robustness in information encoding/transmission and the capability of visible information display through the multi-level color responses, which can implement the multi-level pain warning process of organisms intuitively. Furthermore, different from the conventional multi-modal information processing system that requires independent and complex circuit modules, the proposed SMPS with unique optical multi-information parallel output can realize efficient multi-modal information recognition of dynamic step frequency and spatial positioning simultaneously with the accuracy of 99.5% and 98.2%, respectively. Therefore, the SMPS proposed in this work with simple component, flexible operation, strong robustness, and highly efficiency is promising for future sensory-neuromorphic photonic systems and interactive artificial intelligence.
Devices with sensing-memory-computing capability for the detection, recognition and memorization of real time sensory information could simplify data conversion, transmission, storage, and operations ...between different blocks in conventional chips, which are invaluable and sought-after to offer critical benefits of accomplishing diverse functions, simple design, and efficient computing simultaneously in the internet of things (IOT) era. Here, we develop a self-powered vertical tribo-transistor (VTT) based on MXenes for multi-sensing-memory-computing function and multi-task emotion recognition, which integrates triboelectric nanogenerator (TENG) and transistor in a single device with the simple configuration of vertical organic field effect transistor (VOFET). The tribo-potential is found to be able to tune ionic migration in insulating layer and Schottky barrier height at the MXene/semiconductor interface, and thus modulate the conductive channel between MXene and drain electrode. Meanwhile, the sensing sensitivity can be significantly improved by 711 times over the single TENG device, and the VTT exhibits excellent multi-sensing-memory-computing function. Importantly, based on this function, the multi-sensing integration and multi-model emotion recognition are constructed, which improves the emotion recognition accuracy up to 94.05% with reliability. This simple structure and self-powered VTT device exhibits high sensitivity, high efficiency and high accuracy, which provides application prospects in future human-mechanical interaction, IOT and high-level intelligence.
Selective attention is an efficient processing strategy to allocate computational resources for pivotal optical information. However, the hardware implementation of selective visual attention in ...conventional intelligent system is usually bulky and complex along with high computational cost. Here, programmable ferroelectric bionic vision hardware to emulate the selective attention is proposed. The tunneling effect of photogenerated carriers are controlled by dynamic variation of energy barrier, enabling the modulation of memory strength from 9.1% to 47.1% without peripheral storage unit. The molecular polarization of ferroelectric P(VDF-TrFE) layer enables a single device not only multiple nonvolatile states but also the implementation of selective attention. With these ferroelectric devices are arrayed together, UV light information can be selectively recorded and suppressed the with high current decibel level. Furthermore, the device with positive polarization exhibits high wavelength dependence in the image attention processing, and the fabricated ferroelectric sensory network exhibits high accuracy of 95.7% in the pattern classification for multi-wavelength images. This study can enrich the neuromorphic functions of bioinspired sensing devices and pave the way for profound implications of future bioinspired optoelectronics.
Perovskite materials have exhibited promising potential for universal applications including backlighting, color conversion, and anticounterfeiting labels fabricated using solution processes. ...However, owing to the tendency of those materials to have uncontrollable morphologies and to form large crystals, they cannot be utilized in discontinuous microminiaturization, which is crucial for practical optoelectronic applications. In this research, combining the effects of adding polyvinylpyrrolidone (PVP), precisely controlling the inkjet printing technique, and using a postprocessing procedure, we were able to fabricate in situ crystallized perovskite–PVP nanocomposite microarrays with perfect morphologies. The viscosity of the perovskite precursor increased with the addition of PVP, eliminating the outward capillary flow that induces the coffee-ring effect. In addition, because of the presence of metallic bonds with the CO groups in PVP and the spatial confinement of such a polymer, we were able to fabricate regulated CsPbBr3 nanocrystals capped with PVP and with a uniform size distribution. The as-printed patterns showed excellent homogeneity on a macroscale and high reproducibility on a microscale; furthermore, those patterns were invisible in the ambient environment, compatible with flexible substrates, and cost-efficient to produce, indicating that this technique holds promising potential for applications such as anticounterfeiting labels.
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IJS, KILJ, NUK, PNG, UL, UM
Quantum dot light emitting diodes (QLEDs) are increasingly attractive owing to their compatibility with the inkjet printing process and potential application in low-cost large-area full-color ...pixelated display. The strategy for controlling the morphology of the quantum dot layer is definitely critical for realizing all-solution processed QLEDs with high performance, which certainly requires in-depth thinking regarding the design of ink composition and their optimization in the printing process. Herein, by carefully controlling the quantum dot ink composition and physicochemical properties, we demonstrate that the viscosity, contact angle, and the three-phase contact line moving would affect the final morphology of the quantum dot film formed by inkjet printing. We achieved coffee ring-free and low-roughness quantum dot film, and all-solution processed QLEDs with normal structure were fabricated for the first time. The devices have a low turn-on voltage of 2.0 V, a luminance of 12100 cd/m2 at the voltage of 12 V, and a maximum current efficiency of 4.44 cd/A at the luminance of 1974 cd/m2, which is the best result to date for inkjet-printed red QLEDs. The results will pave the way for future application of inkjet printing in solution processed pixelated QLED display.
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Benefiting from solution processability, material diversity and biocompatibility properties of organic semiconductors, organic synaptic transistor is a promising alternative to execute neuromorphic ...computing. Unfortunately, conventional planner organic synaptic transistors suffer from poor analog weight update and fault tolerance, which limits the pattern recognition accuracy of organic neuromorphic system. Herein, a scalable and reconfigurable nanoscale channel organic ferroelectric synaptic transistor array (NOFST) is firstly demonstrated. Different from planner synaptic devices whose synaptic properties mostly rely on manipulating carrier densities, the operation mechanism of NOFST is associated with the virtual contact formation of pseudo-conductive channel and polarization tuned distribution of carriers, which manipulates the injection of carries into semiconductor. Hence, benefiting from the nanoscale channel length and the above unique operation mechanism, NOFST exhibits excellent gate control ability contributing to the improvement of fault tolerance and weight update properties. Finally, the neuromorphic system built from NOFST achieves 91.38% recognition accuracy of handwriting digit, which is record high for organic field-effect synaptic transistors. The special device structure is wildly applicable for other organic semiconductor materials, providing a new pathway for developing organic neuromorphic hardware systems with high recognition accuracy.
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•The nanoscale channel organic ferroelectric synaptic transistor array is reported for the first time.•The recognition accuracy of NOFST is the recorded high among organic field-effect synaptic transistors.•The operation mechanism of NOFST is associated with the virtual contact formation of pseudo-conductive channel and polarization tuned distribution of carriers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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