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Abstract Binocular stereo vision relies on imaging disparity between two hemispherical retinas, which is essential to acquire image information in three dimensional environment. Therefore, retinomorphic electronics with structural and functional similarities to biological eyes are always highly desired to develop stereo vision perception system. In this work, a hemispherical optoelectronic memristor array based on Ag‐TiO2 nanoclusters/sodium alginate film is developed to realize binocular stereo vision. All‐optical modulation induced by plasmonic thermal effect and optical excitation in Ag‐TiO2 nanoclusters is exploited to realize in‐pixel image sensing and storage. Wide field of view (FOV) and spatial angle detection are experimentally demonstrated owing to the device arrangement and incident‐angle‐dependent characteristics in hemispherical geometry. Furthermore, depth perception and motion detection based on binocular disparity have been realized by constructing two retinomorphic memristive arrays. The results demonstrated in this work provide a promising strategy to develop all‐optically controlled memristor and promote the future development of binocular vision system with in‐sensor architecture.

Abstract Intrinsically stretchable gas sensors possess outstanding advantages in seamless conformability and high‐comfort wearability for real‐time detection toward skin/respiration gases, making them promising candidates for health monitoring and non‐invasive disease diagnosis and therapy. However, the strain‐induced deformation of the sensitive semiconductor layers possibly causes the sensing signal drift, resulting in failure in achievement of the reliable gas detection. Herein, a surprising result that the stretchable organic polymers present a universal strain‐insensitive gas sensing property is shown. All the stretchable polymers with different degrees of crystallinity, including indacenodithiophene‐benzothiadiazole (PIDTBT), diketo‐pyrrolo‐pyrrole bithiophene thienothiophene (DPPT‐TT) and poly[4‐(4,4‐dihexadecyl‐4H‐cyclopenta[1,2‐b:5,4‐b′]dithiophen‐2‐yl)‐alt‐[1,2,5]thiad‐iazolo [3,4‐c] pyridine] (PCDTPT), show almost unchanged gas response signals in the different stretching states. This outstanding advantage enables the intrinsically stretchable devices to imperceptibly adhere on human skin and well conform to the versatile deformations such as bending, twisting, and stretching, with the highly strain‐stable gas sensing property. The intrinsically stretchable PIDTBT sensor also demonstrates the excellent selectivity toward the skin‐emitted trimethylamine (TMA) gas, with a theoretical limit of detection as low as 0.3 ppb. The work provides new insights into the preparation of the reliable skin‐like gas sensors and highlights the potential applications in the real‐time detection of skin gas and respiration gas for non‐invasive medical treatment and disease diagnosis.

Abstract Auditory motion perception is one crucial capability to decode and discriminate the spatiotemporal information for neuromorphic auditory systems. Doppler frequency‐shift feature and interaural time difference (ITD) are two fundamental cues of auditory information processing. In this work, the functions of azimuth detection and velocity detection, as the typical auditory motion perception, are demonstrated in a WOx‐based memristive synapse. The WOx memristor presents both the volatile mode (M1) and semi‐nonvolatile mode (M2), which are capable of implementing the high‐pass filtering and processing the spike trains with a relative timing and frequency shift. In particular, the Doppler frequency‐shift information processing for velocity detection is emulated in the WOx memristor based auditory system for the first time, which relies on a scheme of triplet spike‐timing‐dependent‐plasticity in the memristor. These results provide new opportunities for the mimicry of auditory motion perception and enable the auditory sensory system to be applied in future neuromorphic sensing.

Abstract The surface ligand environment plays a dominant role in determining the physicochemical, optical, and electronic properties of colloidal quantum dots (CQDs). Specifically, the ligand‐related electronic traps are the main reason for the carrier nonradiative recombination and the energetic losses in colloidal quantum dot solar cells (CQDSCs), which are usually solved with numerous advanced ligand exchange reactions. However, the synthesis process, as the essential initial step to control the surface ligand environment of CQDs, has lagged behind these post‐synthesis ligand exchange reactions. The current PbS CQDs synthesis tactic generally uses lead oxide (PbO) as lead precursor, and thus suffers from the water byproducts issue increasing the surface‐hydroxyl ligands and aggravating trap‐induced recombination in the PbS CQDSCs. Herein, an organic‐Pb precursor, lead (II) acetylacetonate (Pb(acac)2), is used instead of a PbO precursor to avoid the adverse impact of water byproducts. Consequently, the Pb(acac)2 precursor successfully optimizes the surface ligands of PbS CQDs by reducing the hydroxyl ligands and increasing the iodine ligands with trap‐passivation ability. Finally, the Pb(acac)2‐based CQDSCs possess remarkably reduced trap states and suppressed nonradiative recombination, generating a certified record Voc of 0.652 V and a champion power conversion efficiency (PCE) of 11.48% with long‐term stability in planar heterojunction‐structure CQDSCs.

Abstract Solution‐processed solar cells are promising for the cost‐effective, high‐throughput production of photovoltaic devices. Colloidal quantum dots (CQDs) are attractive candidate materials for efficient, solution‐processed solar cells, potentially realizing the broad‐spectrum light utilization and multi‐exciton generation effect for the future efficiency breakthrough of solar cells. The emerging quantum junction solar cells (QJSCs), constructed by n‐ and p‐type CQDs only, open novel avenue for all‐quantum‐dot photovoltaics with a simplified device configuration and convenient processing technology. However, the development of high‐efficiency QJSCs still faces the challenge of back carrier diffusion induced by the huge carrier density drop at the interface of CQDs and conductive glass substrate. Herein, an ultra‐thin atomic layer deposited tin oxide (SnOx) layer is employed to buffer this carrier density drop, significantly reducing the interfacial recombination and capacitance caused by the back carrier diffusion. The SnOx‐modified QJSC achieves a record‐high efficiency of 11.55% and a suppressed hysteresis factor of 0.04 in contrast with reference QJSC with an efficiency of 10.4% and hysteresis factor of 0.48. This work clarifies the critical effect of interfacial issues on the carrier recombination and hysteresis of QJSCs, and provides an effective pathway to design high‐performance all‐quantum‐dot devices.

Abstract Biodegradable organic field‐effect transistors (OFETs) have drawn tremendous attention for potential applications such as green electronic skins, degradable flexible displays, and novel implantable devices. However, it remains a huge challenge to simultaneously achieve high mobility, stable operation and controllable biodegradation of OFETs, because most of the widely used biodegradable insulating materials contain large amounts of hydrophilic groups. Herein, it is firstly proposed fungal‐degradation ultraflexible OFETs based on the crosslinked dextran (C‐dextran) as dielectric layer. The crosslinking strategy effectively eliminates polar hydrophilic groups and improves water and solvent resistance of dextran dielectric layer. The device with spin‐coated 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT) semiconductor and C‐dextran dielectric exhibits the highest mobility up to 7.72 cm2 V−1 s−1, which is higher than all the reported degradable OFETs. Additionally, the device still maintains high performance regardless of in an environment humidity up to 80% or under the extreme bending radius of 0.0125 mm. After completion of their mission, the device can be controllably biodegraded by fungi without any adverse environmental effects, promoting the natural ecological cycles with the concepts of “From nature, for nature”. This work opens up a new avenue for realizing high‐performance biodegradable OFETs, and advances the process of the “green” electrical devices in practical applications.

Abstract Exploration of optoelectronic memristors with the capability to combine sensing and processing functions is required to promote development of efficient neuromorphic vision. In this work, the authors develop a plasmonic optoelectronic memristor that relies on the effects of localized surface plasmon resonance (LSPR) and optical excitation in an Ag–TiO2 nanocomposite film. Fully light‐induced synaptic plasticity (e.g., potentiation and depression) under visible and ultraviolet light stimulations is demonstrated, which enables the functional combination of visual sensing and low‐level image pre‐processing (including contrast enhancement and noise reduction) in a single device. Furthermore, the light‐gated and electrically‐driven synaptic plasticity can be performed in the same device, in which the spike‐timing‐dependent plasticity (STDP) learning functions can be reversibly modulated by visible and ultraviolet light illuminations. Thereby, the high‐level image processing function, i.e., image recognition, can also be performed in this memristor, whose recognition rate and accuracy are obviously enhanced as a result of image pre‐processing and light‐gated STDP enhancement. Experimental analysis shows that the memristive switching mechanism under optical stimulation can be attributed to the oxidation/reduction of Ag nanoparticles due to the effects of LSPR and optical excitation. The authors' work proposes a new type of plasmonic optoelectronic memristor with fully light‐modulated capability that may promote the future development of efficient neuromorphic vision.

Abstract As the most extensively used gas‐sensing devices, inorganic semiconductor chemiresistors are facing great challenges in realizing mechanical flexibility and room‐temperature gas detection for developing next‐generation wearable sensing devices. Herein, for the first time, flexible all‐inorganic yttria‐stabilized zirconia (YSZ)/In2O3/graphitic carbon nitride (g‐C3N4) (ZIC) gas sensor is designed by employing YSZ nanofibers as substrate, and ultrathin In2O3/g‐C3N4 heterostructures as active sensing layer. The YSZ substrate possesses small nanofiber diameter (310 nm), ultrafine grain size (23.9 nm), and abundant dangling bonds, endowing it with striking mechanical flexibility and strong adhesion with In2O3/g‐C3N4 sensing layer. Meanwhile, the ultrathin thickness (≈7 nm) of In2O3/g‐C3N4 ensures that the inorganic sensing layer has tiny linear strain along with the deformation of flexible YSZ substrate, thereby enabling unusual bending capacity. To address the operating temperature issue, the gas sensor is operated by using a visible‐light‐powered strategy. Under visible‐light illumination, the flexible ZIC sensor exhibits a perfectly reversible response/recovery dynamic process and ultralow detection limit of 50 ppb to toxic nitrogen dioxide at room temperature. This work not only provides an insight into the mechanical flexibility of inorganic materials, but also offers a valuable reference for developing other flexible inorganic‐semiconductor‐based room‐temperature gas sensors.

Abstract Organic thin‐film transistors (OTFTs) are identified to be the most promising candidate for next‐generation wearable and implantable electronics because of their unique advantages including their flexibility, low cost, long‐term biocompatibility, and simple packaging. However, commercialization of organic transistors remains an enormous challenge due to their low mobility and lack of scalable strategy for high‐precise soft devices. Here, a novel photolithography fabrication strategy is proposed, which is completely compatible with various commercial organic semiconductor materials, for the first demonstration of the fully photolithographic top‐contact conformable OTFTs with the device density as high as 1523 transistors cm−2. Excellent electrical and mechanical properties with device yield as high as 100%, field‐effect mobility up to 1–2 cm2 V−1 s−1, and outstanding conformability are shown. This work provides a new strategy that can fully maximize the advantages of organic materials and photolithography technology, showing a great prospect in the development of high‐performance, high‐precise organic devices toward the commercialized and industrialized soft electronic products.

Abstract Colored wide‐bandgap semiconductor oxides with abundant mid‐gap states have long been regarded as promising visible light responsive photocatalysts. However, their catalytic activities are hampered by charge recombination at deep level defects, which constitutes the critical challenge to practical applications of these oxide photocatalysts. To address the challenge, a strategy is proposed here that includes creating shallow‐level defects above the deep‐level defects and thermal activating the migration of trapped electrons out of the deep‐level defects via these shallow defects. A simple and scalable solution plasma processing (SPP) technique is developed to process the presynthesized yellow TiO2 with numerous oxygen vacancies (Ov), which incorporates hydrogen dopants into the TiO2 lattice and creates shallow‐level defects above deep level of Ov, meanwhile retaining the original visible absorption of the colored TiO2. At elevated temperature, the SPP‐treated TiO2 exhibits a 300 times higher conversion rate for CO2 reduction under solar light irradiation and a 7.5 times higher removal rate of acetaldehyde under UV light irradiation, suggesting the effectiveness of the proposed strategy to enhance the photoactivity of colored wide‐bandgap oxides for energy and environmental applications.