Efficient Carrier Multiplication in Self-Powered Near-Ultraviolet γ-InSe/Graphene Heterostructure Photodetector with External Quantum Efficiency Exceeding 161.

Carrier multiplication (CM) in semiconductors, the process of absorbing a single high-energy photon to form two or more electron-hole pairs, offers great potential for the high-response detection of high-energy photons in the ultraviolet spectrum. However, compared to two-dimensional semiconductors, conventional bulk semiconductors not only face integration and flexibility bottlenecks but also exhibit inferior CM performance. To attain efficient CM for ultraviolet detection, we designed a two-terminal photodetector featuring a unilateral Schottky junction based on a two-dimensional γ-InSe/graphene heterostructure. Benefiting from a strong built-in electric field, the photogenerated high-energy electrons in γ-InSe, an ideal ultraviolet light-absorbing layer, can efficiently transfer to graphene without cooling. It results in efficient CM within the graphene, yielding an ultrahigh responsivity of 468 mA/W and a record-high external quantum efficiency of 161.2% when it is exposed to 360 nm light at zero bias. This work provides valuable insights into developing next-generation ultraviolet photodetectors with high performance and low-power consumption.

Transfer-Printing of Insoluble Conducting Polymer for Soft 3D Conformal All-Organic Transistors.

The development of high-precision insoluble conducting polymer patterns for soft electronics is extremely challenging, mainly because of the incompatibility of the synthesis process with the underlying layers. In this study, a novel transfer-printing method is designed that enables the fabrication of photolithographic insoluble conducting polypyrrole (PPy) electrode patterns on soft substrates with high precision, demonstrating compatibility with various soft organic functional layers. Excellent mechanical stability, good biocompatibility, ultra-smooth surface, and outstanding conformability are observed. The photolithographic PPy electrode patterns, combined with an elastic organic semiconductor and dielectric, produce conformal all-organic transistors with mobility of 1.8 cm2 V-1 s-1. This study paves the way to use insoluble conducting polymers to develop complex, high-density flexible patterns and offers a promising organic electrode for the new-generation soft all-organic electronics.

Dielectric Design of High Dielectric Constant Poly(Urea-Urethane) Elastomer for Low-Voltage High-Mobility Intrinsically Stretchable All-Solution-Processed Organic Transistors.

Stretchable organic transistors for skin-like biomedical applications require low-voltage operation to accommodate limited power supply and safe concerns. However, most of the currently reported stretchable organic transistors operate at relatively high voltages. Decreasing their operational voltage while keeping the high mobility still remains a key challenge. Here, the study presents a new dielectric design to achieve high-dielectric constant poly(urea-urethane) (PUU) elastomer, by incorporating a flexible small-molecular diamine crosslinking agent 4-aminophenyl disulfide (APDS) into the main chain of (poly (propylene glycol), tolylene 2,4-diiso-cyanate terminated) (PPG-TDI). Compared with commercial elastomers, the PUU elastomer as dielectric of the stretchable organic transistors shows the outstanding advantages including lower surface roughness (0.33 nm), higher adhesion (45.18 nN), higher dielectric constant (13.5), as well as higher stretchability (896%). The PUU dielectric enables the intrinsically stretchable, all-solution-processed organic transistor to operate at a low operational voltage down to -10 V, while preserving a substantial mobility of 1.39 cm2 V-1 s-1. Impressively, the transistor also demonstrates excellent electrical stability under repeated switching of 10 000 cycles, and remarkable mechanical robustness when stretched up to 100%. The work opens up a new molecular engineering strategy to successfully realize low-voltage high-mobility stretchable all-solution-processed organic transistors.

Novel intertypic recombination of Echovirus 11 in the Enterovirus species B.

Enteroviruses (EVs), single-stranded, positive-sense RNA viruses, can be classified into four species (A-D), which have previously been linked to a diverse range of disease manifestations and infections affecting the central nervous system. In the Enterovirus species B (EV-B), Echovirus type 11 (E11) has been observed to occasionally circulate in Taiwan, which was responsible for an epidemic of enterovirus infections in 2018. Here, 48 clinical specimens isolated in 2003, 2004, 2009, and 2018 were collected for the high-throughput sequencing. Notably, we identified 2018 Taiwanese strains having potential recombinations in the 3D gene, as well as one 2003 strain having a double recombination with E6 and Coxsackievirus B5 in the P2 and P3 regions, respectively. Additionally, one amino acid signature mutated from the Histidine (H) in throat swab specimens to the Tyrosine (Y) in cerebral spinal fluid specimens was detected at position 1496 (or 57) of the genomic coordinate (or 3A gene) to further demonstrate intra-host evolution in different organs. In conclusion, this study identifies potential intertypic recombination events and an intra-host signature mutation in E11 strains, isolated during a 2018 neurological disease outbreak in Taiwan, contributing to our understanding of its evolution and pathogenesis.

Synergistic Engineering of Energy Band Alignment and Interfacial Electric Field Distribution over Bi-bismuth-Based Hetero-nanofibers for Boosting Visible-Light-Driven Photocatalytic Ammonia Synthesis and Antibiotic Removal.

Synergistic engineering of energy band alignment and interfacial electric field distribution is essential for photocatalyst design but is still challenging because of the limitation on refined regulation in the nanoscale. This study addresses the issue by employing surface modification and thermal-induced phase transformation in Bi2MoO6/BixOyIz hetero-nanofiber frameworks. The energy band alignment switches from a type-II interface to a Z-scheme contact with stronger redox potentials and inhibited electron traps, and the optimized built-in electric field distribution could be reached based on experimental and theoretical investigations. The engineered hetero-nanofibers exhibit outstanding visible-light-driven photocatalytic nitrogen reduction activity (605 µmol/g/h) and tetracycline hydrochloride removal rate (81.5% within 30 min), ranking them among the top-performing bismuth series materials. Furthermore, the photocatalysts show promise in activating advanced oxidants for efficient organic pollutant degradation. Moreover, the Bi2MoO6/Bi5O7I hetero-nanofibers possess good recycling stability owing to their three-dimensional network structure. This research offers valuable insights into heterojunction design for environmental remediation and industrial applications.

Ultrahigh Detectivity Broad Spectrum UV Photodetector with Rapid Response Speed Based on p-ß Ga2 O3 /n-GaN Heterojunction Fabricated by a Reversed Substitution Doping Method.

An excellent broad-spectrum (220-380 nm) UV photodetector, covering the UVA-UVC wavelength range, with an ultrahigh detectivity of ≈1015  cm Hz1/2 W-1 , is reported. It is based on a p-ß Ga2 O3 /n-GaN heterojunction, in which p-ß Ga2 O3 is synthesized by thermal oxidation of GaN and a heterostructure is constructed with the bottom n-GaN. XRD shows the oxide layer is (-201) preferred oriented ß-phase Ga2 O3 films. SIMS and XPS indicate that the residual N atoms as dopants remain in ß Ga2 O3 . XPS also demonstrates that the Fermi level is 0.2 eV lower than the central level of the band gap, indicating that the dominant carriers are holes and the ß Ga2 O3 is p-type conductive. Under a bias of -5 V, the photoresponsivity is 56 and 22 A W-1 for 255 and 360 nm, respectively. Correspondingly, the detectivities reach an ultrahigh value of 2.7 × 1015  cm Hz1/2 W-1 (255 nm) and 1.1 × 1015  cm Hz1/2 W-1 (360 nm). The high performance of this UV photodetector is attributed mainly to the continuous conduction band of the p-ß Ga2 O3 /n-GaN heterojunction without a potential energy barrier, which is more helpful for photogenerated electron transport from the space charge region to the n-type GaN layer.

Multi-Wavelength-Recognizable Memristive Devices via Surface Plasmon Resonance Effect for Color Visual System.

Photoelectric memristor has attracted many attentions thanks to their promising potential in optical communication chips and artificial vision systems. However, the implementation of an artificial visual system based on memristive devices remains a considerable challenge because most photoelectric memristors cannot recognize color. Herein, multi-wavelength recognizable memristive devices based on silver(Ag) nanoparticles (NPs) and porous silicon oxide (SiOx ) nanocomposites are presented. Rely on the effects of localized surface plasmon resonance (LSPR) and optical excitation of Ag NPs in SiOx , the set voltage of the device can be gradually reduced. Moreover, the current overshoot problem is alleviated to suppress conducting filament overgrowth after visible light irradiation with different wavelengths, resulting in diverse low resistance states (LRS). Taking advantage of the characteristics of controlled switching voltage and LRS resistance distribution, color image recognition is finally realized in the present work. X-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (C-AFM) show that the light irradiation plays an important role on resistive switching (RS) process: the photo-assisted Ag ionization leads to a significant reduction of set voltage and overshoot current. This work provides an effective method toward the development of multi-wavelength-recognizable memristive devices for future artificial color vision system.

Multimodal-Synergistic-Modulation Neuromorphic Imaging Systems for Simulating Dry Eye Imaging.

Inspired by human eyes, the neuromorphic visual system employs a highly efficient imaging and recognition process, which offers tremendous advantages in image acquisition, data pre-processing, and dynamic storage. However, it is still an enormous challenge to simultaneously simulate the structure, function, and environmental adaptive behavior of the human eye based on one device. Here, a multimodal-synergistic-modulation neuromorphic imaging system based on ultraflexible synaptic transistors is successfully presented and firstly simulates the dry eye imaging behavior at the device level. Moreover, important functions of the human visual system in relation to optoelectronic synaptic plasticity, image erasure and enhancement, real-time preprocessing, and dynamic storage are simulated by versatile devices. This work not only simplifies the complexity of traditional neuromorphic visual systems, but also plays a positive role in the publicity of biomedical eye care.

The Cellular Characterization of SARS-CoV-2 Spike Protein in Virus-Infected Cells Using the Receptor Binding Domain Binding Specific Human Monoclonal Antibodies.

A human monoclonal antibody panel (PD4, PD5, PD7, SC23, and SC29) was isolated from the B cells of convalescent patients and used to examine the S protein in SARS-CoV-2-infected cells. While all five antibodies bound conformational-specific epitopes within SARS-CoV-2 spike (S) protein, only PD5, PD7, and SC23 were able to bind to the receptor binding domain (RBD). Immunofluorescence microscopy was used to examine the S protein RBD in cells infected with the Singapore isolates SARS-CoV-2/0334 and SARS-CoV-2/1302. The RBD-binders exhibited a distinct cytoplasmic staining pattern that was primarily localized within the Golgi complex and was distinct from the diffuse cytoplasmic staining pattern exhibited by the non-RBD-binders (PD4 and SC29). These data indicated that the S protein adopted a conformation in the Golgi complex that enabled the RBD recognition by the RBD-binders. The RBD-binders also recognized the uncleaved S protein, indicating that S protein cleavage was not required for RBD recognition. Electron microscopy indicated high levels of cell-associated virus particles, and multiple cycle virus infection using RBD-binder staining provided evidence for direct cell-to-cell transmission for both isolates. Although similar levels of RBD-binder staining were demonstrated for each isolate, SARS-CoV-2/1302 exhibited slower rates of cell-to-cell transmission. These data suggest that a conformational change in the S protein occurs during its transit through the Golgi complex that enables RBD recognition by the RBD-binders and suggests that these antibodies can be used to monitor S protein RBD formation during the early stages of infection. IMPORTANCE The SARS-CoV-2 spike (S) protein receptor binding domain (RBD) mediates the attachment of SARS-CoV-2 to the host cell. This interaction plays an essential role in initiating virus infection, and the S protein RBD is therefore a focus of therapeutic and vaccine interventions. However, new virus variants have emerged with altered biological properties in the RBD that can potentially negate these interventions. Therefore, an improved understanding of the biological properties of the RBD in virus-infected cells may offer future therapeutic strategies to mitigate SARS- CoV-2 infection. We used physiologically relevant antibodies that were isolated from the B cells of convalescent COVID-19 patients to monitor the RBD in cells infected with SARS-CoV-2 clinical isolates. These immunological reagents specifically recognize the correctly folded RBD and were used to monitor the appearance of the RBD in SARS-CoV-2-infected cells and identified the site where the RBD first appears.

Exciting-frequency-adaptive amplitude/phase hybrid holographic inscription in plasmonic polymers.

Plasmonic holography is generally regarded as an effective technology for 3D display that meets the requirements of the human visual system. However, low readout stability and large cross talk in the frequency field during a plasmonic photo-dissolution reaction set a huge obstacle for application of color holography. Herein, we propose a new, to the best of our knowledge, route toward producing exciting frequency sensitive holographic-inscription based on plasmonic nano-Ag adaptive growth. Donor-molecule-doped plasmonic polymers on polyethylene terephthalate substrates exhibit wide spectral response range, accurate optical frequency sensing, and bending durability. The resonant plasmonic particles act as optical antennas and transfer energy to surrounding organic matrices for nanocluster production and non-resonant particle growth. The surface relief hologram is also highly dependent on the excitation frequency, so we successfully obtain a controllable cross-periodic structure with amplitude/phase mixed information, as well as color holographic display. This work provides a bright way to high-density storage, information steganography, and virtual/augmented reality.

Speech and Language outcomes in Auditory Neuropathy Spectrum Disorder (ANSD) children managed with amplification.

OBJECTIVE: To evaluate speech and language outcomes in children with Auditory Neuropathy Spectrum Disorder (ANSD) without significant comorbidities who received hearing rehabilitation in the form of hearing aids and/or cochlear implantation. METHODS: Retrospective chart review of pediatric ANSD patients at a large academic tertiary care institution from 2010 to 2019. Patients were included if they received a diagnosis of bilateral ANSD, had minimal to no comorbidities, and had speech and language testing (SLT) on at least two occasions. RESULTS: 51 patients were reviewed and 7 met inclusion criteria. Average age at ANSD diagnosis was 1 year and 11 months, and average age of hearing aid fitting was 3 years and 3 months. Hearing loss ranged from mild to profound, with four of the children wearing behind (BTE) hearing aids and three eventually receiving cochlear implants. Four of five patients who received hearing aids prior to their first speech and language evaluation demonstrated a delay at their initial evaluation, and all five patients continued to demonstrate a delay at their most recent evaluation, despite appropriate audiologic management and speech and language therapy. There were two patients who were unaided at the time of their initial and latest evaluations; one patient showed a delay at both timepoints, and one patient showed no speech delay at either timepoint. CONCLUSIONS: Pediatric ANSD patients, who are otherwise typically developing and received hearing rehabilitation and speech and language therapy, continue to show a speech and language delay (SLD). This outcome underscores the importance of close monitoring of speech and language development, providing early amplification and/or cochlear implantation, and promoting additional education and psychosocial support.

The Effect of Developmental Delay and Autism Spectrum Disorder on External Auditory Canal Foreign Body Extraction.

OBJECTIVES: To determine the effect of developmental delay (DD) and autism spectrum disorder (ASD) on pediatric external auditory canal foreign body (EAC FB) retrieval outcomes. METHODS: A retrospective chart review of children presenting with EAC FB at a tertiary children's hospital was performed between January 2018 and December 2019. Charts were reviewed for demographics, presence of otalgia, complications, number of EAC FB episodes, indications for operating room removal, DD, and ASD status. RESULTS: A total of 1467 patients underwent EAC FB removal. One hundred thirty-seven children (9.3%) had DD, and, of those with DD, 63 (46%) had ASD. Children with DD were 1.76 years older compared with children with non-DD (NDD) ( P < 0.0001) at the time of presentation, whereas children with ASD were 1.45 years older than children with NDD ( P = 0.0023). Children with DD and ASD were more likely to require removal of FB in the operating room (OR) compared with the NDD group (36.5% vs 16.7%, P = 0.0001). This was not true for children with DD without ASD. Patients with DD reported significantly less otalgia when compared with NDD patients (26.3% vs 37.4%, P = 0.0097). A similar trend, although not statistically significant, was observed when comparing children with ASD with NDD patients. The NDD patients (1.1) had fewer EAC FB episodes than patients with DD (1.6, P < 0.0001) and ASD (1.8, P < 0.0016). Hazard ratios for multiple episodes of FB were 4.5 (95% confidence interval, 2.9-6.8) for DD, and 5.6 for ASD (95% confidence interval, 3.2-9.9). The complication rate for all groups was low. CONCLUSIONS: Due to the different ways that children with DD and ASD present compared with NDD children, physicians should be vigilant when evaluating symptoms and conducting physical examinations for EAC FB in those patients. A lower threshold for referral to otolaryngologists may result in more favorable outcomes.

Toripalimab Plus Chemotherapy for Recurrent or Metastatic Nasopharyngeal Carcinoma: The JUPITER-02 Randomized Clinical Trial.

Importance: There are currently no therapies approved by the US Food and Drug Administration for nasopharyngeal carcinoma (NPC). Gemcitabine-cisplatin is the current standard of care for the first-line treatment of recurrent or metastatic NPC (RM-NPC). Objective: To determine whether toripalimab in combination with gemcitabine-cisplatin will significantly improve progression-free survival and overall survival as first-line treatment for RM-NPC, compared with gemcitabine-cisplatin alone. Design, Setting, and Participants: JUPITER-02 is an international, multicenter, randomized, double-blind phase 3 study conducted in NPC-endemic regions, including mainland China, Taiwan, and Singapore. From November 10, 2018, to October 20, 2019, 289 patients with RM-NPC with no prior systemic chemotherapy in the RM setting were enrolled from 35 participating centers. Interventions: Patients were randomized (1:1) to receive toripalimab (240 mg [n = 146]) or placebo (n = 143) in combination with gemcitabine-cisplatin for up to 6 cycles, followed by maintenance with toripalimab or placebo until disease progression, intolerable toxicity, or completion of 2 years of treatment. Main Outcome: Progression-free survival as assessed by a blinded independent central review. Secondary end points included objective response rate, overall survival, progression-free survival assessed by investigator, duration of response, and safety. Results: Among the 289 patients enrolled (median age, 46 [IQR, 38-53 years; 17% female), at the final progression-free survival analysis, toripalimab treatment had a significantly longer progression-free survival than placebo (median, 21.4 vs 8.2 months; HR, 0.52 [95% CI, 0.37-0.73]). With a median survival follow-up of 36.0 months, a significant improvement in overall survival was identified with toripalimab over placebo (hazard ratio [HR], 0.63 [95% CI, 0.45-0.89]; 2-sided P = .008). The median overall survival was not reached in the toripalimab group, while it was 33.7 months in the placebo group. A consistent effect on overall survival, favoring toripalimab, was found in subgroups with high and low PD-L1 (programmed death-ligand 1) expression. The incidence of all adverse events, grade 3 or greater adverse events, and fatal adverse events were similar between the 2 groups. However, adverse events leading to discontinuation of toripalimab or placebo (11.6% vs 4.9%), immune-related adverse events (54.1% vs 21.7%), and grade 3 or greater immune-related adverse events (9.6% vs 1.4%) were more frequent in the toripalimab group. Conclusions and Relevance: The addition of toripalimab to chemotherapy as first-line treatment for RM-NPC provided statistically significant and clinically meaningful progression-free survival and overall survival benefits compared with chemotherapy alone, with a manageable safety profile. These findings support the use of toripalimab plus gemcitabine-cisplatin as the new standard of care for this patient population. Trial Registration: ClinicalTrials.gov Identifier: NCT03581786.

Engineering Relaxation-Paths of C-Exciton for Constructing Band Nesting Bypass in WS2 Monolayer.

Transition-metal dichalcogenides exhibit strong photon absorption characteristics in the band nesting region (denoted as C-exciton) due to intrinsic van Hove singularities despite being atomically thin. However, because of unique parallel band structure and ineluctably unfavorable recombination process, only a small fraction of the hot carriers from C-excitons are converted into optically active band-edge excitons via inherent relaxation-paths. The resultant photoluminescence quantum yield (PLQY) is severely suppressed for the resonant excitation of C-exciton. To overcome this limitation, we have designed double type-I band alignments to construct a band nesting bypass in a monolayer WS2/CdS quantum dot heterostructure for cooling the C-excitons. Transient optical measurements confirmed that the hot carriers from the C-excitons were effectively transferred from WS2 to CdS with an efficiency of 50% and subsequently back to the WS2 band-edge to form A-excitons over an ultrafast subpicosecond time scale, accompanied by a record high PLQY of ∼11.1% for near-resonance C-exciton excitation.

Recognizing the Importance of Fast Nonisothermal Crystallization for High-Performance Two-Dimensional Dion-Jacobson Perovskite Solar Cells with High Fill Factors: A Comprehensive Mechanistic Study.

Two-dimensional (2D) Dion-Jacobson (DJ) perovskite solar cells (PSCs), despite their advantage in versatility of n-layer variation, are subject to poor photovoltaic efficiency, particularly in the fill factor (FF), compared to their three-dimensional counterparts. To enhance the performance of DJ PSCs, the process of growing crystals and hence the corresponding morphology of DJ perovskites are of prime importance. Herein, we report the fast nonisothermal (NIT) crystallization protocol that is previously unrecognized for 2D perovskites to significantly improve the morphology, orientation, and charge transport of the DJ perovskite films. Comprehensive mechanistic studies reveal that the NIT effect leads to the secondary crystallization stage, forming network-like channels that play a vital role in the FF's leap-forward improvement and hence the DJ PSC's performance. As a whole, the NIT crystallized PSCs demonstrate a high power conversion efficiency and an FF of up to 19.87 and 86.16%, respectively. This research thus provides new perspectives to achieve highly efficient DJ PSCs.

Polarization-selective absorptive and transmissive metamaterials.

A polarization sorting metamaterial with polarization filtering and absorption is proposed. When unpolarized incident light strikes the metamaterial, one polarization component is completely absorbed, and the other polarization component is completely transmitted. We achieved an absorption extinction ratio of up to 350 and a transmission extinction ratio of 425 simultaneously in the LWIR. Unlike the 50% energy utilization limit of other polarization absorbers due to the complete reflection of another polarization component, our proposed metamaterial can be composed of layered polarization selective absorption devices to achieve more than 90% energy utilization. Therefore our design can provide a new solution for real-time polarization detection.

Dual-path inscription of plasmonic nano-Ag moiré fringes.

Construction of moiré surface patterns has attracted considerable attention due to the fascinating function of photoelectric manipulation. Holographic inscription offers superposition of two or more sinusoidal gratings to form moiré structures. However, the current material platforms primarily depend on a single process of photoinduced physical property change to build up multicomponent gratings. Herein, we demonstrate a strategy of bidirectional photochemical reaction on mesoporous TiO2 matrices to form plasmonic nano-Ag moiré fringes. This consists of a photoreduction grating from in situ growth of Ag nanoparticles (NPs) and a photooxidation grating utilizing the Schottky interface of Ag/TiO2. The pattern obtained under the superposition of double spatial frequencies exhibits non-equidistant moiré fringes. This Letter provides a pathway for implementing complex surface structures.

Peri-Neural Invasion Is an Important Prognostic Factor of T2N0 Oral Cancer.

Background and objectives: Among patients with pathologically proven T2N0 oral squamous cell carcinoma (OSCC), a notable amount of patients still die from tumor recurrence although they have radical surgery for early stage cancers. In literature, the prognostic indicators of this specific disease entity were rarely reported. This study aims at analyzing the prognostic factors of T2N0 OSCC patients and discussing possible managements to improve the survival. MATERIALS AND METHODS: From January 2012 to December 2017, the data of 166 pathologically proven T2N0 oral cancer patients proved by radical surgery were retrospectively collected. The clinical and pathologic factors including age, gender, tumor differentiation grade, perineural invasion (PNI), angiolymphatic invasion (ALI), margin status, and adjuvant therapy were analyzed by univariate and multivariate analysis to determine their association with disease-specific survival (DSS), and disease-free survival (DFS), which were calculated by Kaplan-Meier method. RESULTS: After median follow up time of 43.5 months, overall 3-year rates of DSS and DFS were 86.1% and 80.1% respectively for our 166 patients. Univariate analysis showed that the 3-year DSS of 90.8% for PNI negative patients was significantly better than DSS of 57.0% for PNI positive patients (p = 0.0006). The 3-year DFS of 84.2% for PNI negative patients was also significantly better than DFS of 54.6% for PNI positive patients (p = 0.001). Further multivariate analysis revealed PNI was the only independent prognostic factor associated with both DSS (Hazard Ratio (HR) = 5.02; 95% Confidence Interval (CI) = 1.99-12.6; p = 0.001), and DFS (HR = 3.92; 95% CI = 1.65-9.32; p = 0.002). Nearly 10% (16) of the 166 patients had adverse pathologic feature of PNI only. In the 11 patients without adjuvant therapy, 5 patients died from OSCC. No patients had recurrence or mortality after they received adjuvant therapy with chemotherapy ± radiotherapy. CONCLUSION: PNI was an independent prognostic factor for T2N0 oral cancer patients. Adjuvant chemotherapy and radiotherapy may benefit the survival of this specific disease entity, but further investigations are needed to elucidate the optimal regimen.

Zeolite-Based Memristive Synapse with Ultralow Sub-10-fJ Energy Consumption for Neuromorphic Computation.

The development of neuromorphic computation faces the appreciable challenge of implementing hardware with energy consumption on the level of a femtojoule per synaptic event to be comparable with the energy consumption of human brain. Controllable ultrathin conductive filaments are needed to achieve such extremely low energy consumption in memristive synapses but their formation is difficult to control owing to their stochastic morphology and unexpected overgrowth. Herein, a zeolite-based memristive synapse is demonstrated for the first time, in which Ag exchange in the sub-nanometer pore closely resembles synaptic Ca2+ dynamics across biomembrane channel. Particularly, the confined ultrasmall pore and low Ag ion migration barrier give the zeolite-based memristive synapse ultralow energy consumption below 10 fJ per synaptic spike, on par with the biological counterpart. Experimental results reveal that the gradual memristive effect is attributed to the dimension modulation of Ag clusters. In addition to emulating inherent cognitive functions through electrical stimulations, the experience-dependent transition of short-term plasticity to long-term plasticity using a chemical modulation method is achieved by treating the initial Ag quantity as a learning experience. The proposed memristors can be used to develop highly efficient memristive neural networks and are considered as a candidate for application in neuromorphic computation.

Broadband long-wave infrared metamaterial absorber based on single-sized cut-wire resonators.

Broadband absorption is critical for the applications of metamaterial absorbers. In this work, a broadband long-wave infrared (LWIR) absorber with classical metal-dielectric-metal configuration is numerically demonstrated. The absorber consists of single-sized cut-wire arrays that show broadband and high extinction ratio, attributed to polarization-selective simultaneous excitation of propagated and localized surface plasmon resonances. The average absorption rate of the TM wave reaches 91.7% and 90% of the incident light is absorbed by the resonator in the wavelength range of 7.5-13.25µm so that the average extinction ratio in the resonator layer reaches 125. The polarization insensitive broadband absorption can be obtained by a cross resonator which can be treated as a pair of cut-wires perpendicular to each other. Our metamaterial absorber with single-sized resonators shows spatially concentrated broadband absorption and may have promising applications for hot-electron devices, infrared imaging, and thermal detection.